#include <bits/stdc++.h>
using namespace std;
int b[100001];
int main(int argc, const char* argv[]) {
  int n, h, ans = 0;
  scanf("%d %d", &n, &h);
  int ma = 0;
  for (int i = 0, a; i < n; i++) {
    scanf("%d %d", &a, &b[i]);
    if (ma < a) ma = a;
  }
  sort(b, b + n);
  for (int i = n - 1; ma > b[i]; i--) {
    h = h - b[i];
    ans++;
    if (h <= 0) {
      printf("%d\n", ans);
      return 0;
    }
  }
  if (h % ma != 0) ans += 1;
  printf("%d\n", ans + h / ma);
  return 0;
}
