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