#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, h;
  int a[100001], b[100001];
  cin >> n >> h;
  for (int t = 0; t < n; t++) {
    cin >> a[t] >> b[t];
  }
  sort(a, a + n);
  sort(b, b + n, greater<int>());
  int amax = a[n - 1];
  int i = 0, cont = 0;
  while (b[i] > amax && h > 0) {
    h -= b[i];
    i++;
    cont++;
  }
  if (h % amax == 0) {
    cont += h / amax;
  } else {
    cont += h / amax + 1;
  }
  cout << cont << "\n";
  return 0;
}
