#include <bits/stdc++.h>
using namespace std;
const long long mod = 10000000007;
int n;
long long h;
long long a[100002];
long long b[100002];
int main() {
  cin >> n >> h;
  for (int i = 0; i < n; i++) {
    cin >> a[i] >> b[i];
  }
  int ma = 0;
  int cnt = 0;
  for (int i = 0; i < n; i++) {
    if (ma < a[i]) ma = a[i];
  }
  sort(b, b + n);
  for (int i = 0; i < n; i++) {
    if (ma < b[i]) {
      h -= b[i];
      cnt++;
      if (h <= 0) {
        cout << cnt << endl;
        ;
        return 0;
      }
    }
  }
  cnt += ceil(double(h) / double(ma));
  cout << cnt << endl;
  ;
}
