#include <bits/stdc++.h>
using namespace std;
inline void OPEN(const string &s) {
  freopen((s + ".in").c_str(), "r", stdin);
  freopen((s + ".out").c_str(), "w", stdout);
}
int n;
long long xa, xb, xi, bi;
pair<pair<long long, long long>, int> pa[100000];
pair<pair<long long, long long>, int> pb[100000];
int main() {
  scanf("%d", &n);
  scanf("%I64d %I64d", &xa, &xb);
  for (int i = 0; i < (n); ++i) {
    scanf("%I64d %I64d", &xi, &bi);
    long long lo = xi * xa + bi;
    long long hi = xi * xb + bi;
    pa[i] = make_pair(make_pair(lo, hi), i);
    pb[i] = make_pair(make_pair(hi, lo), i);
  }
  sort(pa, pa + n);
  sort(pb, pb + n);
  for (int i = 0; i < (n); ++i) {
    if (pa[i].second != pb[i].second) {
      printf("YES\n");
      return 0;
    }
  }
  printf("NO\n");
  return 0;
}
