#include <bits/stdc++.h>
using namespace std;
long long n, h;
long long a[100000], b[100000];
signed main() {
  long long i;
  cin >> n >> h;
  for (i = 0; i < n; i++) {
    cin >> a[i] >> b[i];
  }
  sort(a, a + n, greater<long long>());
  sort(b, b + n, greater<long long>());
  long long remH = h;
  long long ans = 1145141919;
  for (i = 0; i <= n; i++) {
    ans = min(ans, (remH + a[0] - 1) / a[0] + i);
    if (i < n) remH -= b[i];
  }
  cout << ans << endl;
  return 0;
}
