#include <bits/stdc++.h>
using namespace std;
int main() {
  string s1;
  string s2;
  string s3;
  cin >> s1 >> s2 >> s3;
  if (s3.size() != s1.size() + s2.size()) {
    cout << "NO";
  } else {
    map<char, int> m;
    int answer = 0;
    for (int i = 0; i < s1.size(); i++) {
      m[s1[i]]++;
    }
    for (int i = 0; i < s2.size(); i++) {
      m[s2[i]]++;
    }
    for (int i = 0; i < s3.size(); i++) {
      m[s3[i]]--;
    }
    for (auto i : m) {
      if (i.second != 0) {
        cout << "NO";
        return 0;
      }
    }
    cout << "YES";
  }
}
