#define _USE_MATH_DEFINES
#include<iostream>
#include<vector>
#include<algorithm>
#include<cmath>
#include<string>
#include<iomanip>
#include<numeric>
#include<queue>
#include<deque>
#include<stack>
#include<set>
#include<map>
#include<random>
#include<bitset>
#include<cassert>
#include<complex>
#include<fstream>
#include<cstdlib>
#include<functional>
#include<array>
using namespace std;
typedef long long ll;
const int mod=998244353;
const int dx[]={1,0,0,-1},dy[]={0,1,-1,0};
int main(){
	int n,a,b,t;
	cin>>n;
	map<int,pair<int,int>>mp;
	while(cin>>a>>b>>t)
		if(a==0)
			mp[b-t].first++;
		else
			mp[b-t].second++;
	ll ans=0;
	for(auto x:mp)
		ans+=(ll)x.second.first*x.second.second;
	cout<<ans<<endl;
}