#include <bits/stdc++.h>
using namespace std;
int a[100011], b[100011], n, h, ans = 0;
int main() {
  cin >> n >> h;
  for (int i = 0; i < n; i++) cin >> a[i] >> b[i];
  sort(b, b + n);
  reverse(b, b + n);
  for (int i = 0; i < n; i++) {
    h -= b[i];
    ans++;
    if (h <= 0) {
      cout << ans << endl;
      return 0;
    }
  }
  sort(a, a + n);
  reverse(a, a + n);
  ans += h / a[0];
  ans += (int)(h % a[0]) != 0;
  cout << ans << endl;
  return 0;
}
