Not getting the right output for BALLSUM problem on spoj

#include <iostream>
#include <cmath>
#include <algorithm>
using namespace std;

int main() {
    long long int n,k,count,sum,i,j;
    cin>>n>>k;
    while(n!=-1 && k!=-1){
        count = 0;
        sum = (n*(n-1))/2;
        
        for(i=1;i<=n;i++){
            for(j=1;j<=n;j++){
                if(j!=i && (j+i)<=k){
                    count++;
                }
            }
        }
        
        int fact = __gcd(count,sum);
        count = count/fact;
        sum = sum/fact;
        cout<<count<<"/"<<sum<<endl;
        cin>>n>>k;
    }
	return 0;
}

The output should be:
0/1
2/2475
2/15

But my output is:
0/1
4/2475
4/15

link to the problem: https://www.spoj.com/problems/BALLSUM/