#include <bits/stdc++.h>
using namespace std;
int main() {
  string s1, s2, s3;
  cin >> s1 >> s2 >> s3;
  vector<char> v1;
  int n1 = s1.length();
  int n2 = s2.length();
  int n3 = s3.length();
  vector<char> v2;
  for (int i = 0; i < n1; i++) {
    v1.push_back(s1[i]);
  }
  for (int i = 0; i < n2; i++) {
    v1.push_back(s2[i]);
  }
  for (int i = 0; i < n3; i++) {
    v2.push_back(s3[i]);
  }
  sort(v1.begin(), v1.end());
  sort(v2.begin(), v2.end());
  n1 = v1.size();
  n2 = v2.size();
  if (n1 != n2) {
    cout << "NO" << endl;
    return 0;
  }
  for (int i = 0; i < n1; i++) {
    if (v1[i] != v2[i]) {
      cout << "NO" << endl;
      return 0;
    }
  }
  cout << "YES" << endl;
  return 0;
}
