#include <bits/stdc++.h>
using namespace std;
const int INF = 1 << 29;
int a[111111], b[111111];
int main() {
  int n, h, count = 0;
  scanf("%d %d", &n, &h);
  for (int i = 0; i < n; i++) scanf("%d %d", &a[i], &b[i]);
  sort(a, a + n, greater<int>());
  sort(b, b + n, greater<int>());
  for (int i = 0; i < n && b[i] >= a[0] && h; i++) h -= b[i], count++;
  printf("%d\n", count + (h > 0 ? (h + a[0] - 1) / a[0] : 0));
  return 0;
}
