#include <bits/stdc++.h>
using namespace std;
int main() {
  int N, H;
  cin >> N >> H;
  vector<int> a(N);
  vector<int> b(N);
  for (int i = 0; i < N; i++) {
    cin >> a[i] >> b[i];
  }
  sort(a.rbegin(), a.rend());
  sort(b.rbegin(), b.rend());
  int answer = 0;
  for (int i = 0; i < N; i++) {
    if (a[0] <= b[i] && 0 < H) {
      answer++;
      H -= b[i];
    } else {
      break;
    }
  }
  answer += ceil((double)H / a[0]);
  cout << answer << endl;
}
