#include <bits/stdc++.h>
using namespace std;
int main() {
  string s1, s2, s;
  cin >> s1 >> s2 >> s;
  if ((s1.length() + s2.length()) != s.length())
    cout << "NO";
  else {
    map<char, int> mp;
    map<char, int> m;
    for (int i = 0; i < s1.length(); i++) {
      mp[s1[i]]++;
    }
    for (int i = 0; i < s2.length(); i++) {
      mp[s2[i]]++;
    }
    for (int i = 0; i < s.length(); i++) {
      m[s[i]]++;
    }
    if (mp.size() != m.size())
      cout << "NO";
    else {
      int flag = 0;
      for (int i = 0; i < m.size(); i++) {
        if (m[i] != mp[i]) {
          flag = 1;
          break;
        }
      }
      if (flag == 0)
        cout << "YES";
      else
        cout << "NO";
    }
  }
  return 0;
}
