#include <bits/stdc++.h>
using namespace std;
int main() {
  int N, H, ans = 0;
  cin >> N >> H;
  int a, b, a_max = 0;
  vector<int> V;
  for (int i = 0; i < N; i++) {
    cin >> a >> b;
    a_max = max(a, a_max);
    V.push_back(b);
  }
  sort(V.begin(), V.end());
  for (int i = 0; i < N; i++) {
    if (a_max < V[i]) {
      H -= V[i];
      ans += 1;
      if (H <= 0) break;
    }
  }
  if (H > 0) {
    ans += (H / a_max);
    if (H % a_max != 0) ans += 1;
  }
  cout << ans << endl;
}
