#include<iostream>
#include<cmath>
using namespace std;
int main(){
    int n,yw[2000],sx[2000],yy[2000],z[100],sum=0;
    cin>>n;
    for(int i=1;i<=n;i++)
    {
        cin>>yw[i]>>sx[i]>>yy[i];
        z[i]=yw[i]+sx[i]+yy[i];
    }
    for(int i=1;i<=n;i++)
    {
        for(int j=i+1;j<=n;j++)
        {
            if(abs(yw[i]-yw[j])<=5)
            {
                if(abs(sx[i]-sx[j])<=5)
                {
                    if(abs(yy[i]-yy[j])<=5)
                    {
                        if(abs(z[i]-z[j])<=10)
                        {
                          sum++;
                          //cout<<"语文"<<yw[i]<<" "<<yw[j]<<endl;
                          //cout<<"数学"<<sx[i]<<" "<<sx[j]<<endl;
                          //cout<<"英语"<<yy[i]<<" "<<yy[j]<<endl;
                          //cout<<"总分"<<z[i]<<" "<<z[j]<<endl;
                                                 }
                    }
                }
            }
        }
    }
    cout<<sum;
    return 0;
    
}