#include <bits/stdc++.h>
using namespace std;
int main() {
  string guest, host, pile;
  cin >> guest >> host >> pile;
  sort(pile.begin(), pile.end());
  guest.append(host);
  sort(guest.begin(), guest.end());
  if (guest == pile)
    cout << "YES";
  else
    cout << "NO";
  return 0;
}
