#include <bits/stdc++.h>
using namespace std;
int main() {
  long long int n, h, ct = 0;
  vector<long long int> a, b;
  cin >> n >> h;
  for (int i = 0; i < n; i++) {
    long long int tmp1, tmp2;
    cin >> tmp1 >> tmp2;
    a.push_back(tmp1);
    b.push_back(tmp2);
  }
  sort(b.begin(), b.end(), greater<long long int>());
  sort(a.begin(), a.end(), greater<long long int>());
  while (h > 0 && ct < n && a[0] < b[ct]) {
    h -= b[ct];
    ct++;
  }
  if (h > 0) {
    ct += h / a[0];
  }
  cout << ct;
  return 0;
}
