#include <stdio.h>
#include <string.h>
#include <stdbool.h>

#define MAX 2010
#define MOD 32767
#define clr(ar) memset(ar, 0, sizeof(ar))
#define read() freopen("lol.txt", "r", stdin)

int t, n, m, X[MAX], Y[MAX], id[MOD + 6667], hash[MOD + 6667], counter[MOD + 6667];

int F(int i, int j){
    int x = (X[i] - X[j]);
    int y = (Y[i] - Y[j]);
    return ((x * x) + (y * y));
}

int find(int x){
    int i = x & MOD, res = 0;
    while (id[i] == m && hash[i] != x) i++;
    if (id[i] == m){
        res = counter[i];
        counter[i]++;
    }
    else hash[i] = x, counter[i] = 1, id[i] = m;
    return res;
}

int main(){
    int T = 0, i, j, k, l;

    scanf("%d", &t);
    while (t--){
        scanf("%d", &n);
        for (i = 0; i < n; i++) scanf("%d %d", &X[i], &Y[i]);

        long long res = 0;
        for (i = 0; i < n; i++){
            m++;
            for (j = 0; j < n; j++){
                res += find(F(i, j));
            }
        }

        printf("Case #%d: %lld\n", ++T, res);
    }
    return 0;
}