/* -*- coding: utf-8 -*-
 *
 * 1679.cc:  No.1679 マスゲーム - yukicoder
 */

#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<cmath>
#include<iostream>
#include<string>
#include<vector>
#include<map>
#include<set>
#include<stack>
#include<list>
#include<queue>
#include<deque>
#include<algorithm>
#include<numeric>
#include<utility>
#include<complex>
#include<functional>
 
using namespace std;

/* constant */

const int MAX_N = 200000;

/* typedef */

typedef long long ll;
typedef map<int,int> mii;

/* global variables */

mii vs[2];

/* subroutines */

/* main */

int main() {
  // (bi,t+ti)=(t+tj,bj) -> bi=t+tj,t+ti=bj
  // -> t = bi-tj = bj-ti -> bi+ti=bj+tj

  int n;
  scanf("%d", &n);

  for (int i = 0; i < n; i++) {
    int ai, bi, ti;
    scanf("%d%d%d", &ai, &bi, &ti);
    vs[ai][bi + ti]++;
  }

  mii::iterator mit0 = vs[0].begin();
  mii::iterator mit1 = vs[1].begin();
  ll sum = 0;

  while (mit0 != vs[0].end() && mit1 != vs[1].end()) {
    if (mit0->first < mit1->first) mit0++;
    else if (mit0->first > mit1->first) mit1++;
    else {
      sum += (ll)mit0->second * mit1->second;
      mit0++, mit1++;
    }
  }

  printf("%lld\n", sum);
  return 0;
}