#include <bits/stdc++.h>
using namespace std;
long long a[110000], b[110000], n, h, res, k;
int main(void) {
  cin >> n >> h;
  for (long long i = 0; i < n; i++) cin >> a[i] >> b[i];
  sort(a, a + n);
  sort(b, b + n);
  for (long long i = 0; i < n; i++) {
    if (b[i] > a[n - 1]) {
      k = i;
      break;
    }
  }
  for (long long i = n - 1; i >= k; i--) {
    h -= b[i];
    res++;
    if (h <= 0) {
      cout << res << endl;
      return 0;
    }
  }
  cout << res + (h - 1) / a[n - 1] + 1 << endl;
}
