#include <bits/stdc++.h>
using namespace std;
signed main(void) {
  cin.tie(0);
  ios::sync_with_stdio(false);
  long long N, H;
  cin >> N >> H;
  long long a[100010], b[100010];
  long long cnt = 0;
  for (long long i = 0; i < N; i++) {
    cin >> a[i] >> b[i];
  }
  sort(a, a + N, greater<long long>());
  sort(b, b + N, greater<long long>());
  for (long long i = 0; i < N; i++) {
    if (a[0] > b[i]) break;
    H -= b[i];
    cnt++;
    if (H < 0) {
      cout << cnt << endl;
      return 0;
    }
  }
  cout << cnt + (a[0] + H - 1) / a[0] << endl;
  return 0;
}
