#include <bits/stdc++.h>
using namespace std;
int N, H, A[100000], B[100000];
int main() {
  int ans = 0;
  cin >> N >> H;
  for (int i = 0; i < N; i++) {
    cin >> A[i] >> B[i];
  }
  int max_a = 0;
  for (int i = 0; i < N; i++) {
    if (A[i] > max_a) {
      max_a = A[i];
    }
  }
  sort(B, B + N);
  int i = N - 1;
  while (B[i] > max_a) {
    H -= B[i];
    i--;
    ans++;
    if (H < 0) {
      cout << ans << endl;
      return 0;
    }
  }
  while (H > 0) {
    H -= max_a;
    ans++;
  }
  cout << ans << endl;
}
