#include <bits/stdc++.h>
using namespace std;
int main() {
  string s1, s2, con, s3;
  getline(cin, s1);
  getline(cin, s2);
  cin >> s3;
  con = s1 + s2;
  sort(s3.begin(), s3.end());
  sort(con.begin(), con.end());
  if (s3 == con) {
    cout << "YES";
  } else {
    cout << "NO";
  }
}
