#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());
  sort(b.begin(), b.end());
  reverse(a.begin(), a.end());
  reverse(b.begin(), b.end());
  int ans = 0;
  for (int i = 0; i < b.size(); i++) {
    if (a[0] < b[i]) {
      H -= b[i];
      ans++;
    }
  }
  if (H <= 0) {
    cout << ans << endl;
    return 0;
  }
  if (H % a[0] == 0)
    ans += H / a[0];
  else
    ans += H / a[0] + 1;
  cout << ans << endl;
}
