#include <bits/stdc++.h>
using namespace std;
int main(void) {
  int h, i, j, k, n, y, a[100000], b[100000], ans = 0, amax = 0;
  scanf("%d %d", &n, &h);
  for (i = 0; i < n; i++) {
    scanf("%d %d", &a[i], &b[i]);
    if (a[i] > amax) amax = a[i];
  }
  sort(b, b + n);
  i = n - 1;
  while (b[i] > amax) {
    h -= b[i];
    ans++;
    if (h <= 0) {
      printf("%d\n", ans);
      return 0;
    }
    i--;
  }
  while (h >= 0) {
    h -= amax;
    ans++;
  }
  printf("%d\n", ans);
  return 0;
}
