#include <bits/stdc++.h>
using namespace std;
int main() {
  long long int n, h;
  cin >> n >> h;
  vector<pair<long long int, long long int>> pa, pb;
  long long int ans = 0;
  for (int i = 0; i < n; i++) {
    long long int a, b;
    cin >> a >> b;
    pa.push_back(make_pair(a, b));
    pb.push_back(make_pair(b, a));
  }
  sort(pa.rbegin(), pa.rend());
  sort(pb.rbegin(), pb.rend());
  int j = 0;
  while (pa[0].first < pb[j].first) {
    ans++;
    h -= pb[j].first;
    j++;
    if (j > n - 1) {
      break;
    }
  }
  ans += (h + pa[0].first - 1) / pa[0].first;
  cout << ans << endl;
  return 0;
}
