#include<bits/stdc++.h>
using namespace std;
constexpr int Inf = 2000000000;
constexpr long long INF= 2000000000000000000;
 
template<typename T> inline bool chmax(T &a, T b) { if (a < b) { a = b; return true; } return false; }
template<typename T> inline bool chmin(T &a, T b) { if (a > b) { a = b; return true; } return false; }

template<typename T,typename U>
T modpow(T N, U P, T M = -1){
    if(P < 0) return 0;
    T ret = 1;
    if(M != -1) ret %= M;
    while(P) {
        if(P & 1) {
            if(M == -1) ret *= N;
            else ret = ret * N % M;
        }
        P /= 2;
        if(M == -1) N *= N;
        else N = N * N % M;
    }
    return ret;
}

int main() {
    int N;
    cin >> N;
    map<int,long long> Red;
    map<int,long long> Blue;
    for(int i = 0;i < N;i++) {
        int A,B,T;
        cin >> A >> B >> T;
        if(A == 0) Red[B - T]++;
        else Blue[B - T]++;
    }
    long long ret = 0;
    for(auto& [key,value] : Red) {
        ret += value * Blue[key];
    }
    cout << ret << endl;
}