#include <bits/stdc++.h>
using namespace std;
int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  int n, h;
  cin >> n >> h;
  int a, max_a = 0, b[n];
  for (int i = 0; i < n; i++) {
    cin >> a >> b[i];
    if (a > max_a) max_a = a;
  }
  sort(b, b + n, greater<int>());
  int ans = 0;
  for (int i = 0; b[i] >= max_a && h >= 0 && i < n; i++) {
    h -= b[i];
    ans++;
  }
  while (h > 0) {
    h -= max_a;
    ans++;
  }
  cout << ans << "\n";
  return 0;
}
