#include <bits/stdc++.h>
using namespace std;
int main() {
  long long n, h;
  cin >> n >> h;
  vector<long long> a(n), b(n);
  for (int i = 0; i < n; ++i) {
    cin >> a.at(i) >> b.at(i);
  }
  sort(b.begin(), b.end());
  const long long maxa = *max_element(a.begin(), a.end());
  long long ans = (h + maxa - 1) / maxa;
  for (int i = n - 1; i >= 0; --i) {
    h -= b.at(i);
    ans = min(ans, n - i + (h + maxa - 1) / maxa);
  }
  cout << ans << endl;
  return 0;
}
