#include <bits/stdc++.h>
#define rep(i,n) for(int i = 0; i < (n); i++)
using namespace std;
typedef long long ll;

int main(){
    cin.tie(0);
    ios::sync_with_stdio(0);
    
    int N; cin >> N;
    vector<tuple<int,int,int>> A(N);
    for(auto &[a, b, t] : A) cin >> a >> b >> t;
    map<int,int> mp;
    for(auto [a, b, t] : A) if(a == 0) mp[b - t]++;
    ll ans = 0;
    for(auto [a, b, t] : A) if(a == 1) ans += mp[b - t];
    cout << ans << endl;
}