Uniform Generator

#include <cstdio>
#include <set>
using namespace std;
set<int> S;
int main()
{
int s,m;
while(scanf("%d%d",&s,&m)!=EOF){
S.clear();
int x=s%m;
S.insert(x);
while(1){
x=(x+s)%m;
if(S.count(x)==1)break;
else S.insert(x);
}
int n=S.size();
if(n!=m)printf("%10d%10d    Bad Choice\n",s,m);
else printf("%10d%10d    Good Choice\n",s,m);
printf("\n");
}
return 0;
}