#include <bits/stdc++.h>
using namespace std;
int main() {
  int freq1[26] = {0}, freq2[26] = {0};
  string s1, s2, s, s3;
  cin >> s1 >> s2 >> s;
  s3 = s1 + s2;
  for (int i = 0; i < s.length(); i++) {
    freq1[s[i] - 'A']++;
    freq2[s3[i] - 'A']++;
  }
  bool t = true;
  for (int i = 0; i < 26; i++) {
    if (freq1[i] != freq2[i]) {
      t = false;
      break;
    }
  }
  if (t == true && s.length() == s3.length())
    cout << "YES" << endl;
  else
    cout << "NO" << endl;
  return 0;
}
