#include <stdio.h>
#include <stdlib.h>

int main(void) {
    int N;
    int i, j, temp;
    int sum1;
    int grade[1000][3];
    int sum[1000];
    temp = 0;
    scanf("%d", &N);
    for (i = 0; i < N; i++) {
        scanf("%d %d %d", &grade[i][0], &grade[i][1], &grade[i][2]);
        sum[i] = grade[i][0] + grade[i][1] + grade[i][2];
    }
    for (i = 0; i < N; i++) {
        for (j = i + 1; j < N; j++) {
            if (abs(grade[i][0] - grade[j][0]) <= 5 &&
                abs(grade[i][1] - grade[j][1]) <= 5 &&
                abs(grade[i][2] - grade[j][2]) <= 5 &&
                abs(sum[i] - sum[j]) <= 5) {
                temp++;
            }
        }
    }
    printf("%d", temp);
    return 0;
}