#include <bits/stdc++.h>
using namespace std;
int main() {
  string s1, s2, s3;
  cin >> s1 >> s2 >> s3;
  int s3Len = s3.length();
  for (int i = 0; i < s1.length(); i++) {
    int loc = s3.find(s1[i]);
    if (loc != -1) s3.erase(loc, 1);
  }
  for (int i = 0; i < s2.length(); i++) {
    int loc = s3.find(s2[i]);
    if (loc != -1) s3.erase(loc, 1);
  }
  if (s3.empty() && s1.length() + s2.length() == s3Len)
    cout << "YES" << endl;
  else
    cout << "NO" << endl;
  return 0;
}
