#include <bits/stdc++.h>
using namespace std;
int main(void) {
  int n, h;
  cin >> n >> h;
  vector<int> a(n), b(n);
  for (int i = 0; i < n; ++i) {
    cin >> a[i] >> b[i];
  }
  sort(a.rbegin(), a.rend());
  sort(b.rbegin(), b.rend());
  vector<long long> bb(n + 1);
  bb[0] = 0;
  for (int i = 0; i < n; ++i) {
    bb[i + 1] = bb[i] + b[i];
  }
  long long ans = INT_MAX;
  for (int i = 0; i <= n; ++i) {
    long long cnt = i + ceil(((double)h - bb[i]) / a[0]);
    ans = min(ans, cnt);
  }
  cout << ans << endl;
  return 0;
}
