#include <bits/stdc++.h>
using namespace std;
int main() {
  long long n, h;
  cin >> n >> h;
  vector<long long> a(n);
  vector<long long> b(n);
  long long i;
  for (i = 0; i < n; ++i) {
    cin >> a.at(i) >> b.at(i);
  }
  sort(a.begin(), a.end());
  sort(b.begin(), b.end());
  reverse(a.begin(), a.end());
  reverse(b.begin(), b.end());
  long long maxa = a.at(0);
  long long ans = 0;
  long long modeb = 0;
  while (h > 0) {
    if (b.at(modeb) > maxa && modeb < n) {
      h -= b.at(modeb);
      ++ans;
      ++modeb;
    } else {
      h -= maxa;
      ++ans;
    }
  }
  cout << ans << endl;
  return 0;
}
