#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];
    cin >> b[i];
  }
  sort(a.begin(), a.end());
  sort(b.begin(), b.end());
  reverse(b.begin(), b.end());
  int count = 0;
  for (int i = 0; i < N; i++) {
    if (b[i] < a[N - 1]) break;
    H -= b[i];
    count++;
  }
  while (H > 0) {
    H -= a[N - 1];
    count++;
  }
  cout << count << endl;
}
