#include <iostream>

using namespace std;

int main()
{
    int m; int n; bool q=false;
    short int a[50000], b[50000];
    cin >> m;
    for (int i=1; i<=m; i++)
        cin >> a[i];
    cin >> n;
    for (int j=1; j<=n; j++)
    {
        cin >> b[j];
        if (!q) for (int i=1; i<=m; i++)
        {
            if ((a[i]+b[j])==10000) { q=true; break; }
            if ((a[i]+b[j])>10000) break;
        }
    }
    if (q) cout << "YES"; else cout << "NO";
    return 0;
}

Where is the error?

arrays first index=0. I changed
short int a[50007], b[50007];
and got AC:
http://acm.timus.ru/status.aspx?space=1&num=1021&author=63786

Thanks very much! Accepted for me!