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