超时

#include<iostream>
#include<string>
using namespace std;

void reverse(string& a)
{
    int len = a.size();
    for(int i = 0; i < len/2; ++i)
    {
        char t = a[i];
        a[i] = a[len-i-1];
        a[len-i-1] = t;
    }
}

void exchange(string& a, int& flag1, string& b, int& flag2)
{
    int flag = flag1;
    flag1 = flag2;
    flag2 = flag;
    string t(a);
    a = b;
    b = t;
}

int judge(char ch)
{
    if(ch == '-')
        return -1;
    return 1;
}

void f(string& a)
{
    int k = 0;
    if(a[0] == '+' || a[0] == '-')
        k =1;
    string s(a.begin()+k, a.end());
    a = s;
}

char f2(char& ch)
{
    ch = (ch >= 'A' )? (ch-'A'+10):(ch-'0');
    return ch;
}
char f3(char& ch)
{
    ch = (ch > 9)?(ch-10+'A'):(ch+'0');
    return ch;
}
int add(string& a, string& b)
{
    int c = 0, i;
    for(i = 0; i < b.size(); ++i)
    {
        a[i] = f2(a[i]) + f2(b[i]) + c;
        c = a[i] / 16;
        a[i] %= 16;
        f3(a[i]);
    }
    while(i < a.size())
    {
        a[i] = f2(a[i]) + c;
        c = a[i] / 16;
        a[i] %= 16;
        f3(a[i]);
    }
    reverse(a);
    return c;
}
int cut(string& a, string& b)
{
    int c = 0, i;
    for(i = 0; i < b.size(); ++i)
    {
        if(f2(a[i])+c < f2(b[i]))
        {
            a[i] = char(f2(a[i]) + 16 + c - f2(b[i]));
            c = -1;
        }
        else
        {
            a[i] = char(f2(a[i]) + c - f2(b[i]));
            c = 0;
        }
        f3(a[i]);
    }
    while(i < a.size() && c < 0)
    {
        if(f2(a[i]) + c < 0)
        {
            a[i] = char(f2(a[i]) + 16 + c);
            c = -1;
        }
        else
        {
            a[i] = char(f2(a[i]) + c);
            c = 0;
            break;
        }
        f3(a[i]);
        ++i;
    }
    reverse(a);
    return c;
}

void out(string& a, int flag, int c)
{
    if(flag < 0)
        cout << '-';
    if(c)
        cout << c;
    cout << a << endl;
}
int main()
{
    string a, b;
    while(cin >> a >> b)
    {
        int flag1 = 1, flag2 = 1;
        flag1=judge(a[0]);
        flag2 = judge(b[0]);
        f(a);
        f(b);
        if(a.size() < b.size())
            exchange(a, flag1, b, flag2);
        else if(a.size() == b.size() && a < b)
            exchange(a, flag1, b, flag2);
        reverse(a);
        reverse(b);
        int c = 0;
        if(flag1 * flag2 > 0)
            c = add(a, b);
        else
            c = cut(a, b);
        out(a, flag1, c);
    }
    return 0;
}

#include <iostream>
#include <iomanip>
using namespace std;
int main()
{
    __int64 a,b,c;
    while(cin>>hex>>a>>b){
        c=a+b;
        if(c<0){
         cout<<'-';    
         c=-c;
        }
        cout<<hex<<uppercase<<c<<endl;
        
    }
    return 0;
}

#include<stdio.h>
using namespace std;
int main()
{
    __int64 a,b;
    while(scanf("%I64X %I64X",&a,&b)!=EOF)
    {
        if(a+b<0)
            printf("-%I64X\n",-a-b);
        else
            printf("%I64X\n",a+b);
    }
    return 0;
}