#include <bits/stdc++.h>
using namespace std;
int main(int argc, char const *argv[]) {
  int n, h;
  cin >> n >> h;
  int a[n], b[n];
  for (int i = 0; i < n; ++i) {
    cin >> a[i] >> b[i];
  }
  sort(a, a + n);
  reverse(a, a + n);
  sort(b, b + n);
  reverse(b, b + n);
  int ans = 0;
  for (int i = 0; i < n; ++i) {
    if (a[0] < b[i]) {
      ++ans;
      h -= b[i];
      if (h <= 0) {
        break;
      }
    } else {
      break;
    }
  }
  cout << ans + (h + a[0] - 1) / a[0] << endl;
  return 0;
}
