#include<bits/stdc++.h>
using namespace std;
struct student
{
    int chinese,math,english,all;
};
student a[1010];
int main()
{
    int n,sum=0;
    cin>>n;
    for (int i=1;i<=n;i++)
    {
        cin>>a[i].chinese>>a[i].math>>a[i].english;
        a[i].all=a[i].chinese+a[i].math>>a[i].english;
    }
    for (int i=1;i<n;i++)
    {
        for (int j=i+1;j<=n;j++)
        {
            if (abs(a[i].chinese-a[j].chinese)<=5&&abs(a[i].math-a[j].math<=5)&&abs(a[i].english-a[j].english)<=5&&abs(a[i].all-a[j].all)<=10)
            {
                sum++;
            }
        }
    }
    cout<<sum;
    return 0;
}