#include <bits/stdc++.h>
using namespace std;
typedef long long LL;
const int N=1e2+10;

int main()
{
    int T,cas=1,n,x;
    scanf("%d",&T);
    while(T--)
    {
        scanf("%d",&n);
        int up=0;
        int down=n;
        for(int i=1;i<=n;i++)
        {
            scanf("%d",&x);
            up+=abs(x);
            if(x<0)
                down--;
        }
        if(!down)
            printf("Case %d: inf\n",cas++);
        else
        {
            int g=__gcd(up,down);
            printf("Case %d: %d/%d\n",cas++,up/g,down/g);
        }
    }
    return 0;
}