#include <bits/stdc++.h>
using namespace std;
int n, a[100005], b[100005], p, q;
double l, r = 1, y, m1, m2, d;
double F(double x) {
  y = 1;
  for (int i = 1; i <= n; i++) y = min(y, (1 - a[i] * x) / b[i]);
  return x * p + q * y;
}
int main() {
  cin >> n, cin >> p, cin >> q;
  for (int i = 1; i <= n; i++) cin >> a[i], cin >> b[i], r = min(r, 1.0 / a[i]);
  while (r - l > 1e-15) {
    d = (r - l) / 3, m1 = l + d, m2 = r - d;
    if (F(m1) > F(m2))
      r = m2;
    else
      l = m1;
  }
  printf("%.8lf\n", F(l));
}
