#include <bits/stdc++.h>
using namespace std;
int main() {
  std::ios::sync_with_stdio(false);
  std::cin.tie(0);
  int n, h;
  cin >> n >> h;
  vector<int> a(n), b(n);
  for (int i = 0; i < n; i++) {
    cin >> a[i] >> b[i];
  }
  int max_a = *max_element(a.begin(), a.end());
  sort(b.rbegin(), b.rend());
  int ans = 0;
  int sum = 0;
  for (int i = 0; i < n; i++) {
    if (b[i] < max_a || sum > h) {
      break;
    }
    sum += b[i];
    ans += 1;
  }
  while (sum < h) {
    sum += max_a;
    ans += 1;
  }
  cout << ans << "\n";
  return 0;
}
