#include <bits/stdc++.h>
using namespace std;
int main(void) {
  long int N, H, a, b;
  long int atop = -1;
  cin >> N >> H;
  long int B[N];
  for (int i = 0; i < N; i++) {
    cin >> a >> b;
    atop = max(atop, a);
    B[i] = b;
  }
  sort(B, N + B);
  long int ans = ceil(H / atop);
  long int cnt = 0;
  int tmp, c;
  for (long int i = N - 1; i >= 0; i--) {
    H -= B[i];
    cnt++;
    c = ceil(H / atop);
    tmp = max(0, c);
    ans = min(ans, cnt + tmp);
  }
  cout << ans << endl;
  return 0;
}
