#include <bits/stdc++.h>
using namespace std;
int main() {
  int H, N;
  cin >> N >> H;
  vector<int> a(N), b(N);
  int a_max = 0;
  int ans = 0;
  for (int i = 0; i < N; i++) {
    cin >> a[i] >> b[i];
    if (a[i] > a_max) a_max = a[i];
  }
  for (int i = 0; i < N; i++) {
    if (b[i] > a_max) {
      H -= b[i];
      ans += 1;
      if (H <= 0) {
        cout << ans << endl;
        return 0;
      }
    }
  }
  ans += (H / a_max);
  if (H % a_max != 0) {
    ans += 1;
  }
  cout << ans << endl;
  return 0;
}
