#include <bits/stdc++.h>
using namespace std;
int N, H;
int a[10000];
int b[10000];
int main(int argc, char *args[]) {
  int counter = 0;
  cin >> N >> H;
  for (int i = 0; i < N; i++) {
    cin >> a[i] >> b[i];
  }
  sort(a, a + N);
  sort(b, b + N);
  int a_max = a[N - 1];
  for (int i = N - 1; i >= 0; i--) {
    if (a_max >= b[i]) break;
    counter = counter + 1;
    H = H - b[i];
    if (H <= 0) break;
  }
  if (H > 0) {
    counter += (H + a_max - 1) / a_max;
  }
  cout << counter << endl;
}
