#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, h;
  cin >> n >> h;
  vector<int> a(n);
  vector<int> b(n);
  for (int i = 0; i < n; i++) {
    cin >> a[i] >> b[i];
  }
  sort(a.begin(), a.end());
  sort(b.begin(), b.end());
  int sum = 0;
  int i = n - 1;
  while (i >= 0) {
    if (b[i] > a[n - 1]) {
      h -= b[i];
      sum++;
    }
    i--;
  }
  sum += h / a[n - 1];
  cout << sum;
  return 0;
}
