#include<bits/stdc++.h>
using namespace std;

bool pd(int x1,int x2,int x3,int y1,int y2,int y3)
{
    if(x1-y1<=5&&x2-y2<=5&&x3-y3<=5&&(x1+x2+x3)-(y1+y2+y3)<=10)
        return 1;
    else
        return 0;
}

int main()
{
    int n,sum=0;
    scanf("%d",&n);
    int x1[n],x2[n],x3[n];
    for(int i = 1;i <= n;i++)
    {
        scanf("%d %d %d",&x1[i],&x2[i],&x3[i]);
    }
    for(int i = n;i >= 1;i--)
    {
        for(int j =1;j <= i;j++)
        {
            if(pd(x1[i],x2[i],x3[i],x1[j],x2[j],x3[j]))
            {
                sum++;
            }
        }
    }
    printf("%d",sum);
    return 0;
}