#include <bits/stdc++.h>
using namespace std;
int main() {
  string s, s1, s2;
  cin >> s >> s1 >> s2;
  char l[s.size() + s1.size()];
  for (int i = 0; i < s.size(); i++) {
    l[i] = s[i];
  }
  for (int i = s.size(); i < s.size() + s1.size(); i++) {
    l[i] = s1[i - s.size()];
  }
  bool b = true;
  for (int i = 0; i < s2.size(); i++) {
    bool bo = false;
    for (int j = 0; j < s.size() + s1.size(); j++) {
      if (s2[i] == l[j]) {
        bo = true;
        l[j] = 'a';
        break;
      }
    }
    if (bo == false) {
      b = false;
    }
  }
  if (s.size() + s1.size() > s2.size()) {
    b = false;
  }
  if (b == true) {
    cout << "YES";
  }
  if (b == false) {
    cout << "NO";
  }
  return 0;
}
