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