#include <bits/stdc++.h>
using namespace std;
int8_t sign(int a, int b, int &c, int x, int y) {
  return a * 1LL * x + b * 1LL * y + c < 0LL ? -1 : 1;
}
void solve() {
  int x, y, x1, y1;
  cin >> x >> y >> x1 >> y1;
  int16_t ans = 0;
  int16_t n;
  cin >> n;
  for (int i = 0, u, v, c; i < n; i++) {
    cin >> u >> v >> c;
    ans += sign(u, v, c, x, y) != sign(u, v, c, x1, y1);
  }
  cout << ans;
}
int32_t main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  int tkd = 1;
  while (tkd-- > 0) {
    solve();
  }
}
