#include <bits/stdc++.h>
using namespace std;
int main() {
  long N, H;
  cin >> N >> H;
  vector<long> a(N);
  vector<long> b(N);
  for (int i = 0; i < N; i++) {
    cin >> a[i];
    cin >> b[i];
  }
  long a_max = 0;
  long a_m = 0;
  long b_m = 0;
  long long ans = 0;
  for (double i = 0; i < N; i++) {
    if (a[a_max] < a[i]) {
      a_max = i;
    }
  }
  a_m = a[a_max];
  b_m = b[a_max];
  a[a_max] = 0;
  b[a_max] = 0;
  sort(a.begin(), a.end());
  sort(b.begin(), b.end());
  for (int i = N - 1; i > 0; i--) {
    if (a_m <= b[i]) {
      H -= b[i];
      ans += 1;
    }
    if (H <= 0) break;
  }
  if (H > 0) {
    while (1) {
      if (H <= b_m) {
        ans += 1;
        break;
      }
      ans += 1;
      H -= a_m;
    }
  }
  cout << ans << endl;
  return 0;
}
