#include <bits/stdc++.h>
using namespace std;
int a[100006], b[100006];
int main() {
  int i, j;
  int n, h;
  int res = 0;
  scanf("%d %d", &n, &h);
  for (i = 1; i <= n; i++) scanf("%d %d", &a[i], &b[i]);
  sort(a + 1, a + 1 + n);
  sort(b + 1, b + 1 + n);
  for (i = n; b[i] > a[n] and h > 0; i--) {
    h -= b[i];
    res++;
  }
  printf("%.0lf", res + ceil(1.0 * h / a[n]));
  return 0;
}
