#include <bits/stdc++.h>
#include <atcoder/all>
using namespace atcoder;
using namespace std;
using ll=long long;
using ld=long double;
ld pie=3.141592653589793;
ll mod=998244353;
ll inf=1009999999999999990;
int main(){
    ll n;
    cin >> n;
    vector<ll>a(n),b(n),t(n);
    vector<ll>aa(500000,0),bb(500000,0);
    vector<pair<ll,pair<ll,ll>>>p(n);
    ll geta=200000;
    ll ans=0;
    for (ll i = 0; i < n; i++)
    {
        cin >> a[i] >> b[i] >> t[i];
        if (a[i]==0)
        {
            aa[b[i]-t[i]+geta]++;
            ans+=bb[b[i]-t[i]+geta];
        }else{
            bb[b[i]-t[i]+geta]++;
            ans+=aa[b[i]-t[i]+geta];
        }
    }
    cout << ans << endl;
}