#include <bits/stdc++.h>
using namespace std;
const int MAXN = 1e5 + 10;
pair<long long, long long> P[MAXN], st[MAXN];
int main() {
  int n;
  scanf("%d", &n);
  for (int i = 1; i <= n; i++)
    scanf("%lld%lld", &P[i].first, &P[i].second),
        P[i].second -= P[i].first * P[i].first;
  sort(P + 1, P + 1 + n,
       [](pair<long long, long long> x, pair<long long, long long> y) {
         return x.first == y.first ? x.second > y.second : x.first < y.first;
       });
  int k = 0;
  st[++k] = P[1];
  for (int i = 2; i <= n; i++) {
    if (P[i].first != st[k].first) {
      while (k > 1 &&
             (st[k].first - st[k - 1].first) * (P[i].second - st[k].second) -
                     (st[k].second - st[k - 1].second) *
                         (P[i].first - st[k].first) >=
                 0)
        k--;
      st[++k] = P[i];
    }
  }
  printf("%d", k - 1);
  return 0;
}
