#include <bits/stdc++.h>
using namespace std;
int n, h, s, ans, ans2;
pair<int, int> arr[100005], arr2[100005];
int main() {
  scanf("%d%d", &n, &h);
  for (int i = 0; i < n; i++) {
    int a, b;
    scanf("%d%d", &a, &b);
    arr[i] = make_pair(a, b);
    arr2[i] = make_pair(b, a);
  }
  sort(arr, arr + n);
  reverse(arr, arr + n);
  int cur = 0;
  for (int i = 0; i < n; i++)
    if (arr[i].second > arr[0].first) {
      if (cur >= h) {
        printf("%d", ans2);
        return 0;
      }
      cur += arr[i].second;
      ans2++;
    }
  ans2 += (h - cur + arr[0].first - 1) / arr[0].first;
  printf("%d", ans2);
}
