#include <bits/stdc++.h>
using namespace std;
bool compare(int x, int y) { return x > y; }
int main() {
  int n, h, a[100010], b[100010], mx, ans;
  cin >> n >> h;
  for (int i = 0; i < n; i++) cin >> a[i] >> b[i];
  sort(a, a + n, compare);
  mx = a[0];
  sort(b, b + n, compare);
  for (int i = 0; i < n; i++)
    if (b[i] > mx && h > 0) {
      h -= b[i];
      ans++;
    }
  if (h > 0) ans += (h + mx - 1) / mx;
  cout << ans;
  system("pause");
  return 0;
}
