#include <bits/stdc++.h>
using namespace std;
int main() {
  string str1, str2;
  cin >> str1 >> str2;
  long long n1 = str1.length(), n2 = str2.length();
  string str;
  cin >> str;
  long long n = str.length();
  int hash1[26] = {0}, hash2[26] = {0};
  for (int i = 0; i < n1; i++) {
    hash1[str1[i] - 'A']++;
  }
  for (int i = 0; i < n2; i++) {
    hash1[str2[i] - 'A']++;
  }
  for (int i = 0; i < n; i++) {
    hash2[str[i] - 'A']++;
  }
  int f = 0;
  for (int i = 0; i < 26; i++) {
    if (hash1[i] != hash2[i]) {
      f = 1;
      break;
    }
  }
  if (f == 0) {
    cout << "YES"
         << "\n";
  } else {
    cout << "NO"
         << "\n";
  }
}
