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#include <cstdio>
#include <cstdlib>
#include <algorithm>
#include <map>

using namespace std;

void dodaj(map<int, int> &M, int w, int t) {
	if (M.find(t-w) != M.end()) {
		M[t-w]++;
	} else {
		M[t-w] = 1;
	}
	
}

void wypisz(map<int, int> &M) {
	for (map<int, int>::iterator it = M.begin(); it != M.end(); it++ ) {
		printf("%d = %d\n", it->first, it->second);
	}
	printf("\n");
}

int main() {
	int n;
	scanf("%d\n", &n);
	map<int, int> A, B;
	
	for (int i = 0; i < n; ++i) {
		int r, w, t;
		scanf("%d %d %d", &r, &w, &t);
		if (r == 1) {
			dodaj(A, w, t);
		} else {
			dodaj(B, w, t);
		}
	}
	//wypisz(A);
	//wypisz(B);
	map<int, int>::iterator it, jt;
	it = A.begin();
	jt = B.begin();
	int r = 0;
	while (it != A.end() && jt != B.end()) {
		while (it != A.end() && jt != B.end() && it->first < jt->first) {
			++it;
		}
		while (it != A.end() && jt != B.end() && jt->first < it->first) {
			++jt;
		}
		if (it != A.end() && jt != B.end() && it->first == jt->first) {
			r += min(it->second, jt->second);
			++it; ++jt;
		}
	}
	printf("%d\n", r);
	return 0;
}