#include<bits/stdc++.h>
using namespace std;
int main()
{int ans=0;

int chinese[1000],math[1000],english[1000],tol[1000];
int n;
cin>>n;
for(int i=1;i<=n;i++)
{cin>>chinese[i]>>math[i]>>english[i];
tol[i]=chinese[i]+math[i]+english[i];
}
for(int j=1;j<=n;j++){
for (int l=j+1;l<=n;l++)
  {
   if(abs(chinese[j]-chinese[l])<=5&&abs(math[j]-math[l])<=5&&english[j]-english[l]<=5&&tol[j]-tol[l]<=5)
        ans++;

  }


}
cout<<ans;

    return 0;
}