#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, h;
  int a[n], b[n];
  cin >> n >> h;
  int maxa = 0;
  for (int i = 0; i < n; i++) {
    cin >> a[i] >> b[i];
    maxa = max(maxa, a[i]);
  }
  sort(b, b + n);
  reverse(b, b + n);
  int cnt = 0;
  for (int i = 0; i < n; i++) {
    if (h <= 0) {
      cout << cnt << endl;
      return 0;
    }
    h -= b[i];
    cnt++;
  }
  cnt += ceil(h / maxa);
  cout << cnt << endl;
  return 0;
}
