#include <bits/stdc++.h>
using namespace std;
string amuse(string s1, string s2, string s3) {
  int l1 = s1.length();
  int l2 = s2.length();
  int l3 = s3.length();
  if (l3 != l1 + l2) {
    return "NO\n";
  }
  int f1[26], f2[26];
  for (int i = 0; i < 26; i++) {
    f1[i] = 0;
    f2[i] = 0;
  }
  for (int i = 0; i < l1; i++) {
    f1[s1[i] - 'A']++;
  }
  for (int i = 0; i < l2; i++) {
    f1[s2[i] - 'A']++;
  }
  for (int i = 0; i < l3; i++) {
    f2[s3[i] - 'A']++;
  }
  for (int i = 0; i < 26; i++) {
    if (f1[i] != f2[i]) {
      return "NO\n";
    }
  }
  return "YES\n";
}
int main() {
  string s1, s2, s3;
  cin >> s1 >> s2 >> s3;
  cout << amuse(s1, s2, s3);
}
