#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  long long h;
  cin >> n >> h;
  long long a[n], b[n];
  long long ma = 0;
  for (int i = 0; i < n; i++) {
    cin >> a[i] >> b[i];
    ma = max(a[i], ma);
  }
  sort(b, b + n, greater<int>());
  long long ans = 0;
  for (int i = 0; i < n; i++) {
    if (b[i] > ma) {
      ans++;
      h -= b[i];
    }
    if (h < 0) {
      cout << ans << endl;
      return 0;
    }
  }
  ans += h / ma;
  if (h % ma != 0) ans++;
  cout << ans << endl;
  return 0;
}
