#include <bits/stdc++.h>
using namespace std;
int main() {
  int i, j, t;
  string s1, s2, s3, s;
  cin >> s1;
  cin >> s2;
  cin >> s3;
  s = s1 + s2;
  sort(s.begin(), s.end());
  sort(s3.begin(), s3.end());
  if (s == s3) {
    cout << "YES" << endl;
  } else {
    cout << "NO" << endl;
  }
  return 0;
}
