#include <bits/stdc++.h>
#define REP_(i, a_, b_, a, b, ...) \
  for (int i = (a), END_##i = (b); i < END_##i; ++i)
#define REP(i, ...) REP_(i, __VA_ARGS__, __VA_ARGS__, 0, __VA_ARGS__)
using i64 = long long;

void print() { std::cout << "\n"; }
template<class T>
void print(const T &x) {
  std::cout << x << "\n";
}
template<typename Head, typename... Tail>
void print(const Head &head, Tail... tail) {
  std::cout << head << " ";
  print(tail...);
}

struct Input {
  template<typename T>
  operator T() const {
    T x;
    std::cin >> x;
    return x;
  }
} in;

#ifdef MY_DEBUG
#include "debug_dump.hpp"
#else
#define DUMP(...)
#endif

using namespace std;

int m0[400020];
int m1[400020];
const int kOffset = 200010;

auto solve() {
  const int n = in;
  int mx = 0, mn = 2 * kOffset;
  REP(i, n) {
    const int a = in, b = in, t = in;
    int x = b - t + kOffset;
    if (a == 0) {
      ++m0[x];
    } else {
      ++m1[x];
    }
    mx = max(mx, x);
    mn = min(mn, x);
  }
  i64 ans = 0;
  for (int i = mn; i <= mx; ++i) {
    ans += i64(m0[i]) * m1[i];
  }
  return ans;
}

int main() {
  ios_base::sync_with_stdio(false), cin.tie(nullptr);
  print(solve());
}