#include <bits/stdc++.h>
using namespace std;
int main() {
  long long int n, h;
  cin >> n >> h;
  long long int a[n], b[n];
  for (int i = 0; i < n; i++) {
    cin >> a[i] >> b[i];
  }
  sort(a, a + n);
  sort(b, b + n);
  long long int min = 1000000000000;
  long long int cur = 0;
  for (int i = 0; i < n; i++) {
    if (b[i] >= a[n - 1]) {
      h -= b[i];
      cur++;
    }
    if (h <= 0 && cur < min) min = cur;
  }
  if (h > 0) {
    cur += ((h / a[n - 1]) + 1 - 1 * (h % a[n - 1] == 0));
    min = cur;
  }
  cout << min << endl;
  return 0;
}
