#include <bits/stdc++.h>
using namespace std;
int main() {
  string s, s1, s3, s4 = "";
  cin >> s >> s1 >> s3;
  s4 += s1 + s;
  int flag = 1;
  if (s4.length() != s3.length())
    cout << "NO";
  else {
    sort(s4.begin(), s4.end());
    sort(s3.begin(), s3.end());
    for (int i = 0; i < s4.length(); i++) {
      if (s3[i] != s4[i]) {
        flag = 0;
        break;
      }
    }
    if (flag)
      cout << "YES";
    else
      cout << "NO";
  }
  return 0;
}
