#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, h, ans = 0;
  cin >> n >> h;
  vector<pair<int, int>> a(n), b(n);
  for (int i = 0; i < n; i++) {
    scanf("%d%d", &a[i].first, &b[i].first);
    a[i].second = b[i].second = i + 1;
  }
  sort(a.begin(), a.end());
  sort(b.begin(), b.end());
  int i = n - 1;
  while (a[n - 1].first <= b[i].first && h > 0 && i >= 0) {
    h -= b[i].first;
    ans++;
    i--;
  }
  cout << ans + (h + a[n - 1].first - 1) / a[n - 1].first << endl;
  return 0;
}
