#include <bits/stdc++.h>
using namespace std;
int main() {
  string s1, s3, s2, i;
  cin >> s1 >> s2 >> s3;
  s1 = s1 + s2;
  sort(s1.begin(), s1.end());
  sort(s3.begin(), s3.end());
  if (s1 != s3)
    cout << "NO" << endl;
  else
    cout << "YES" << endl;
}
