#include <bits/stdc++.h>
using namespace std;
int a[100005];
int main() {
  int n, h, mx = 0, x, ans = 0;
  scanf("%d%d", &n, &h);
  for (int i = 1; i <= n; i++) scanf("%d%d", &x, &a[i]), mx = max(mx, x);
  std::sort(a + 1, a + n + 1);
  for (int i = n; i; i--) {
    if (a[i] < mx || h < 0) break;
    h -= a[i];
    ans++;
  }
  if (h > 0) ans += (h / mx + (h % mx ? 1 : 0));
  printf("%d\n", ans);
  return 0;
}
