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