#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  long long 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(a.begin(), a.end(), greater<long long>());
  sort(b.begin(), b.end(), greater<long long>());
  long long maxa = a[0];
  long long ans = 0;
  vector<long long>::iterator it = b.begin();
  while (*it > maxa && it != b.end()) {
    ans++;
    if (h <= *it) {
      break;
    } else {
      h -= *it;
      it++;
    }
  }
  if (h > 0) {
    ans += h / maxa;
  }
  cout << ans << endl;
}
