我这是怎么了？

#include<bits/stdc++.h>
using namespace std;
char a[7];
char b[7];
int main()
{
    int i,s1=1,s2=1;
    gets(a);
    gets(b);
    for(i=0;i<6;i++)
    {
        if(a[i]==0) break;
        s1=s1*(a[i]-64);
    }
    for(i=0;i<6;i++)
    {
        if(b[i]==0) break;
        s2=s2*(b[i]-64);
    }
    s1=s1%47;
    s2=s2%47;
    if(s1==s2) cout<<"GO";
    else cout<<"STAY";
    return 0;
} 
![](C:\Users\Administrator\Desktop\洛谷\测试点)