#include <bits/stdc++.h>
using namespace std;
int main() {
  int k = 0;
  int a, b, c;
  string s1, s2, s3;
  cin >> s1 >> s2 >> s3;
  a = s1.size();
  b = s2.size();
  c = s3.size();
  if ((a + b) != c) {
    cout << "NO";
    return 0;
  }
  s1 = s1 + s2;
  for (int i = 0; i < c; i++) {
    for (int j = 0; j < c; j++) {
      if (s1[i] == s3[j]) {
        k++;
        s3[j] = '0';
        break;
      }
    }
  }
  if (k == c)
    cout << "YES";
  else
    cout << "NO";
  return 0;
}
