2073

#include<iostream>
#include<algorithm>
#include<cstdio>
#include<cstring>
#include<string>
using namespace std;

const int maxn=2005;
int vis[maxn];

int main()
{
    int t,k;
    string str;
    cin>>t;
    while(t--)
    {
        int j;
        cin>>str>>k;
        while(k--)
        {
            j=0;
            while(j<str.size()-1&&str[j]<=str[j+1])
                j++;
            str.erase(j,1);
        }
        j=0;
        while(str[j]=='0')
            j++;
        str.erase(0,j);
        if(str.size()==0)
            cout<<"0"<<endl;
        else
            cout<<str<<endl;
    }
    return 0;
}