#include <bits/stdc++.h>
using namespace std;
int main(){
	int n,sum = 0;
	cin >> n;
	int arr[n + 1][4];
	for (int i = 1;i <= n;i++){
		for (int j = 1;j <= 3;j++){
                cin >>arr[i][j];      //输入 #1     3							   	  
									  //			90 90 90        arr[1][1] arr[1][2] arr[1][3]
								   	  //			85 95 90		arr[2][1] arr[2][2] arr[2][3]
								      //			80 100 91		arr[3][1] arr[3][2] arr[3][3]
								      //输出 #1
								      //            2      
		}
	}
	for (int i = 1;i <= n;i++){
		for (int j = i + 1;j <= n;j++){
			if (arr[i][1] - arr[j][1] <= 5 && arr[i][2] - arr[j][2] <= 5 && arr[i][3] - arr[j][3] <= 5){
				if ((arr[i][1] + arr[i][2] + arr[i][3]) - (arr[j][1] + arr[j][2] + arr[j][3]) <= 10){
					sum++;
				}
			}
		}
	}
	cout << sum;
	return 0;
}