#include <bits/stdc++.h>
using namespace std;
int main(void) {
  long long int n, h;
  cin >> n >> h;
  long long int* a = new long long int[n];
  long long int* b = new long long int[n];
  for (int i = 0; i < n; i++) {
    cin >> a[i] >> b[i];
  }
  sort(a, a + n);
  sort(b, b + n);
  long long int count = 0;
  for (int i = 0; i < n; i++) {
    if (b[n - i - 1] < a[n - 1]) break;
    h -= b[n - i - 1];
    if (h < 0) {
      count++;
      cout << count << endl;
      return 0;
    }
    count++;
  }
  long long int c2 = h / a[n - 1];
  if (h - a[n - 1] * c2) c2++;
  cout << count + c2 << endl;
  return 0;
}
