Educational Codeforces Round 90 (Rated for Div. 2) E

#include<map>
#include<queue>
#include<time.h>
#include<limits.h>
#include<cmath>
#include<ostream>
#include<iterator>
#include<set>
#include<stack>
#include<cstdio>
#include<cstring>
#include<iostream>
#include<algorithm>
using namespace std;
#define rep(i,m,n) for(int i=m;i<=n;i++)
#define mem(st) memset(st,0,sizeof st)
int read()
{
    int res=0,ch,flag=0;
    if((ch=getchar())=='-')             //判断正负
        flag=1;
    else if(ch>='0'&&ch<='9')           //得到完整的数
        res=ch-'0';
    while((ch=getchar())>='0'&&ch<='9')
        res=res*10+ch-'0';
    return flag?-res:res;
}
typedef long long ll;
typedef pair<int,int> pii;
typedef unsigned long long ull;
typedef pair<double,double> pdd;
const int inf = 0x3f3f3f3f;
const int maxn=1e6+10;
int mp[200][10]=
{
    {      1,      0,      0,      0,      0,      0,      0,      0,      0,      0},
    {      2,      0,      0,      0,      0,      0,      0,      0,      0,      0},
    {      3,      1,      0,      0,      0,      0,      0,      0,      0,      0},
    {      4,      0,      0,      0,      0,      0,      0,      0,      0,      0},
    {      5,      2,      0,      0,      0,      0,      0,      0,      0,      0},
    {      6,      0,      1,      0,      0,      0,      0,      0,      0,      0},
    {      7,      3,      0,      0,      0,      0,      0,      0,      0,      0},
    {      8,      0,      0,      0,      0,      0,      0,      0,      0,      0},
    {      9,      4,      2,      0,      0,      0,      0,      0,      0,      0},
    {     19,      9,      0,      1,      0,      0,      0,      0,      0,      0},
    {     29,      5,      0,      0,      0,      0,      0,      0,      0,      0},
    {     39,     19,      3,      0,      0,      0,      0,      0,      0,      0},
    {     49,      6,      0,      0,      0,      0,      0,      0,      0,      0},
    {     59,     29,      0,      2,      0,      0,      0,      0,      0,      0},
    {     69,      7,      4,      9,      1,      0,      0,      0,      0,      0},
    {     79,     39,      0,      0,      0,      0,      0,      0,      0,      0},
    {     89,      8,      0,      0,      0,      0,      0,      0,      0,      0},
    {     99,     49,      5,      3,      0,      0,      0,      0,      0,      0},
    {    199,     18,      0,     19,      9,      0,      0,      0,      0,      0},
    {    299,     59,      0,      8,      2,      0,      0,      0,      0,      0},
    {    399,     28,      6,      0,      0,      1,      0,      0,      0,      0},
    {    499,     69,      0,      4,      0,      0,      0,      0,      0,      0},
    {    599,     38,      0,     29,      8,      0,      0,      0,      0,      0},
    {    699,     79,      7,     18,     19,      9,      0,      0,      0,      0},
    {    799,     48,      0,      7,      3,      0,      0,      0,      0,      0},
    {    899,     89,      0,      5,      0,      0,      0,      0,      0,      0},
    {    999,     58,     17,     39,      7,      2,      0,      0,      0,      0},
    {   1999,    189,      0,     28,     18,      0,      1,      0,      0,      0},
    {   2999,     68,      0,     17,     29,      0,      0,      0,      0,      0},
    {   3999,    289,     27,      6,      4,      7,      9,      0,      0,      0},
    {   4999,     78,      0,     49,      6,      0,      0,      0,      0,      0},
    {   5999,    389,      0,     38,     17,      0,      8,      0,      0,      0},
    {   6999,     88,     37,     27,     28,      3,      0,      0,      0,      0},
    {   7999,    489,      0,     16,     39,      0,      7,      0,      0,      0},
    {   8999,     98,      0,     59,      5,      0,      2,      0,      0,      0},
    {   9999,    589,     47,     48,     16,      5,      6,      1,      0,      0},
    {  19999,    198,      0,     37,     27,      0,     19,      9,      0,      0},
    {  29999,    689,      0,     26,     38,      0,      5,      8,      0,      0},
    {  39999,    298,     57,     69,     49,      4,     18,      7,      0,      0},
    {  49999,    789,      0,     58,     15,      0,      4,      6,      0,      0},
    {  59999,    398,      0,     47,     26,      0,     17,      5,      0,      0},
    {  69999,    889,     67,     36,     37,     15,      3,      4,      0,      0},
    {  79999,    498,      0,     79,     48,      0,     16,      3,      0,      0},
    {  89999,    989,      0,     68,     59,      0,     29,      2,      0,      0},
    {  99999,    598,     77,     57,     25,     14,     15,     19,      1,      0},
    { 199999,   1989,      0,     46,     36,      0,     28,     18,      0,      1},
    { 299999,    698,      0,     89,     47,      0,     14,     17,      0,      2},
    { 399999,   2989,     87,     78,     58,     25,     27,     16,      0,      3},
    { 499999,    798,      0,     67,     69,      0,     13,     15,      0,      4},
    { 599999,   3989,      0,     56,     35,      0,     26,     14,      0,      5},
    { 699999,    898,     97,    189,     46,     24,     39,     13,      0,      6},
    { 799999,   4989,      0,     88,     57,      0,     25,     12,      0,      7},
    { 899999,    998,      0,     77,     68,      0,     38,     29,      0,      8},
    { 999999,   5989,    197,     66,     79,     35,     24,     28,     11,      9},
    {1999999,   1998,      0,    289,     45,      0,     37,     27,      0,     10},
    {2999999,   6989,      0,    188,     56,      0,     23,     26,      0,     11},
    {3999999,   2998,    297,     87,     67,     34,     36,     25,      0,     12},
    {4999999,   7989,      0,     76,     78,      0,     49,     24,      0,     13},
    {5999999,   3998,      0,    389,     89,      0,     35,     23,      0,     14},
    {6999999,   8989,    397,    288,     55,     45,     48,     22,      0,     15},
    {7999999,   4998,      0,    187,     66,      0,     34,     39,      0,     16},
    {8999999,   9989,      0,     86,     77,      0,     47,     38,      0,     17},
    {9999999,   5998,    497,    489,     88,     44,     33,     37,     21,     18},
    {      0,  19989,      0,    388,    189,      0,     46,     36,      0,     19},
    {      0,   6998,      0,    287,     65,      0,     59,     35,      0,     20},
    {      0,  29989,    597,     96,     76,     55,     45,     34,      0,     21},
    {      0,   7998,      0,    589,     87,      0,     58,     33,      0,     22},
    {      0,  39989,      0,    488,    188,      0,     44,     32,      0,     23},
    {      0,   8998,    697,    387,    289,     54,     57,     49,      0,     24},
    {      0,  49989,      0,    196,     75,      0,     43,     48,      0,     25},
    {      0,   9998,      0,    689,     86,      0,     56,     47,      0,     26},
    {      0,  59989,    797,    588,    187,     65,     69,     46,     31,     27},
    {      0,  19998,      0,    487,    288,      0,     55,     45,      0,     28},
    {      0,  69989,      0,    296,    389,      0,     68,     44,      0,     29},
    {      0,  29998,    897,    789,     85,     64,     54,     43,      0,     30},
    {      0,  79989,      0,    688,    186,      0,     67,     42,      0,     31},
    {      0,  39998,      0,    587,    287,      0,     53,     59,      0,     32},
    {      0,  89989,    997,    396,    388,     75,     66,     58,      0,     33},
    {      0,  49998,      0,    889,    489,      0,     79,     57,      0,     34},
    {      0,  99989,      0,    788,     95,      0,     65,     56,      0,     35},
    {      0,  59998,   1997,    687,    286,     74,     78,     55,     41,     36},
    {      0, 199989,      0,    496,    387,      0,     64,     54,      0,     37},
    {      0,  69998,      0,    989,    488,      0,     77,     53,      0,     38},
    {      0, 299989,   2997,    888,    589,     85,     63,     52,      0,     39},
    {      0,  79998,      0,    787,    195,      0,     76,     69,      0,     40},
    {      0, 399989,      0,    596,    386,      0,     89,     68,      0,     41},
    {      0,  89998,   3997,   1989,    487,     84,     75,     67,      0,     42},
    {      0, 499989,      0,    988,    588,      0,     88,     66,      0,     43},
    {      0,  99998,      0,    887,    689,      0,     74,     65,      0,     44},
    {      0, 599989,   4997,    696,    295,    185,     87,     64,     51,     45},
    {      0, 199998,      0,   2989,    486,      0,     73,     63,      0,     46},
    {      0, 699989,      0,   1988,    587,      0,     86,     62,      0,     47},
    {      0, 299998,   5997,    987,    688,     94,    189,     79,      0,     48},
    {      0, 799989,      0,    796,    789,      0,     85,     78,      0,     49},
    {      0, 399998,      0,   3989,    395,      0,    188,     77,      0,     50},
    {      0, 899989,   6997,   2988,    586,    285,     84,     76,      0,     51},
    {      0, 499998,      0,   1987,    687,      0,    187,     75,      0,     52},
    {      0, 999989,      0,    896,    788,      0,     83,     74,      0,     53},
    {      0, 599998,   7997,   4989,    889,    194,    186,     73,     61,     54},
    {      0,1999989,      0,   3988,    495,      0,    289,     72,      0,     55},
    {      0, 699998,      0,   2987,    686,      0,    185,     89,      0,     56},
    {      0,2999989,   8997,    996,    787,    385,    288,     88,      0,     57},
    {      0, 799998,      0,   5989,    888,      0,    184,     87,      0,     58},
    {      0,3999989,      0,   4988,    989,      0,    287,     86,      0,     59},
    {      0, 899998,   9997,   3987,    595,    294,     93,     85,      0,     60},
    {      0,4999989,      0,   1996,    786,      0,    286,     84,      0,     61},
    {      0, 999998,      0,   6989,    887,      0,    389,     83,      0,     62},
    {      0,5999989,  19997,   5988,    988,    485,    285,     82,     71,     63},
    {      0,1999998,      0,   4987,   1989,      0,    388,    189,      0,     64},
    {      0,6999989,      0,   2996,    695,      0,    284,    188,      0,     65},
    {      0,2999998,  29997,   7989,    886,    394,    387,    187,      0,     66},
    {      0,7999989,      0,   6988,    987,      0,    193,    186,      0,     67},
    {      0,3999998,      0,   5987,   1988,      0,    386,    185,      0,     68},
    {      0,8999989,  39997,   3996,   2989,    585,    489,    184,      0,     69},
    {      0,4999998,      0,   8989,    795,      0,    385,    183,      0,     70},
    {      0,9999989,      0,   7988,    986,      0,    488,     92,      0,     71},
    {      0,5999998,  49997,   6987,   1987,    494,    384,    289,     81,     72},
    {      0,19999989,      0,   4996,   2988,      0,    487,    288,      0,     73},
    {      0,6999998,      0,   9989,   3989,      0,    293,    287,      0,     74},
    {      0,29999989,  59997,   8988,    895,    685,    486,    286,      0,     75},
    {      0,7999998,      0,   7987,   1986,      0,    589,    285,      0,     76},
    {      0,39999989,      0,   5996,   2987,      0,    485,    284,      0,     77},
    {      0,8999998,  69997,  19989,   3988,    594,    588,    283,      0,     78},
    {      0,49999989,      0,   9988,   4989,      0,    484,    192,      0,     79},
    {      0,9999998,      0,   8987,    995,      0,    587,    389,      0,     80},
    {      0,59999989,  79997,   6996,   2986,    785,    393,    388,     91,     81},
    {      0,19999998,      0,  29989,   3987,      0,    586,    387,      0,     82},
    {      0,69999989,      0,  19988,   4988,      0,    689,    386,      0,     83},
    {      0,29999998,  89997,   9987,   5989,    694,    585,    385,      0,     84},
    {      0,79999989,      0,   7996,   1995,      0,    688,    384,      0,     85},
    {      0,39999998,      0,  39989,   3986,      0,    584,    383,      0,     86},
    {      0,89999989,  99997,  29988,   4987,    885,    687,    292,      0,     87},
    {      0,49999998,      0,  19987,   5988,      0,    493,    489,      0,     88},
    {      0,99999989,      0,   8996,   6989,      0,    686,    488,      0,     89},
    {      0,59999998, 199997,  49989,   2995,    794,    789,    487,    191,     90},
    {      0,199999989,      0,  39988,   4986,      0,    685,    486,      0,    181},
    {      0,69999998,      0,  29987,   5987,      0,    788,    485,      0,    182},
    {      0,299999989, 299997,   9996,   6988,    985,    684,    484,      0,    183},
    {      0,79999998,      0,  59989,   7989,      0,    787,    483,      0,    184},
    {      0,399999989,      0,  49988,   3995,      0,    593,    392,      0,    185},
    {      0,89999998, 399997,  39987,   5986,    894,    786,    589,      0,    186},
    {      0,499999989,      0,  19996,   6987,      0,    889,    588,      0,    187},
    {      0,99999998,      0,  69989,   7988,      0,    785,    587,      0,    188},
    {      0,599999989, 499997,  59988,   8989,   1985,    888,    586,    291,    189},
    {      0,199999998,      0,  49987,   4995,      0,    784,    585,      0,    190},
    {      0,699999989,      0,  29996,   6986,      0,    887,    584,      0,    281},
    {      0,299999998, 599997,  79989,   7987,    994,    693,    583,      0,    282},
    {      0,799999989,      0,  69988,   8988,      0,    886,    492,      0,    283},
    {      0,399999998,      0,  59987,   9989,      0,    989,    689,      0,    284},
    {      0,899999989, 699997,  39996,   5995,   2985,    885,    688,      0,    285},

};
void solve()
{
    int n,k;
    cin>>n>>k;
    if(k==0)
    {
        if(n%9)
            cout<<n%9;
        for(int i=1;i<=n/9;i++)
            cout<<9;
        cout<<endl;
        return ;
    }
    if(mp[n-1][k]!=0)
    {
        cout<<mp[n-1][k]<<endl;
        return ;
    }
    if(mp[n-1][k]==0)
    {
        int ans=0;
        for(int i=0; i<=k; i++)
        {
            int t=i;
            while(t)
            {
                ans+=t%10;
                t/=10;
            }
        }
        if(ans==n)
        {
            cout<<"0"<<endl;
            return ;
        }
        else
        { 
            cout<<"-1"<<endl;
            return; 
        } 
    }
    else
        cout<<mp[n-1][k]<<endl;
}
signed main()
{
    int t;
    cin>>t;
    while(t--)
        solve();
    return 0;
}