#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 ans = 0;
  for (int i = 0; i < n; i++) {
    if (h <= 0) {
      cout << ans << endl;
      return 0;
    }
    h -= b[i];
    ans++;
  }
  cout << ans + floor((double)h / a[0]) << endl;
}
