#include <bits/stdc++.h>
using namespace std;
#include <atcoder/all>
using namespace atcoder;
using ll=long long;
using Graph=vector<vector<int>>;
#define MAX 2000005
//#define MOD 1000000007
#define MOD 998244353
#define INF 1000000000
//#define INF 1000000000000000000

int main(){
  int N;
  cin>>N;
  map<int,int> m1,m2;
  for(int i=0;i<N;i++){
    int A,B,T;
    cin>>A>>B>>T;
    if(A==0){
      m1[B-T]++;
    }else{
      m2[B-T]++;
    }
  }
  ll ans=0;
  for(auto p1:m1){
    ans+=(ll)p1.second*(ll)m2[p1.first];
  }
  cout<<ans<<'\n';
}