#include <bits/stdc++.h>
using namespace std;
void run_case() {
  string A, B, C, D;
  cin >> A;
  cin >> B;
  C = (A + B);
  sort(C.begin(), C.end());
  cin >> D;
  sort(D.begin(), D.end());
  if (C == D)
    cout << "YES\n";
  else
    cout << "NO\n";
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  long long T = 1;
  while (T--) run_case();
  return 0;
}
