#include<bits/stdc++.h>
typedef long long ll;
using namespace std;
const int N=10010;
int chi[N],mat[N];
int eng[N],tot[N];
int ans,n;;
int main(){
	
	cin.sync_with_stdio(false);
	ios::sync_with_stdio(0);
	cin>>n;
	for(int i=1;i<=n;++i){
		cin>>chi[i]>>mat[i]>>eng[i];
		tot[i]=chi[i]+mat[i]+eng[i];
	}
	for(int i=1;i<=n;i++){
		for(int j=i+1;j<=n;j++){
			if((abs(chi[i]-chi[j])<=5)&&(abs(mat[i]-mat[j])<=5)&&(abs(eng[i]-eng[j])<=5)&&(abs(tot[i]-tot[j])<=10)){
				ans++;
			}
		}
	}
	cout<<ans;
	
	
	return 0;
}