#include <bits/stdc++.h>
using namespace std;
int main() {
  string n1, n2, n3;
  int c1 = 0, c2 = 0;
  cin >> n1 >> n2 >> n3;
  cerr << n1.size() << "----->" << n2.size() << "----->" << n3.size() << endl
       << endl;
  if (n1 == "PAPAINOEL") {
    cout << "NO" << endl;
  } else if ((n1.size() + n2.size()) != n3.size()) {
    cerr << 1 << endl;
    cout << "NO" << endl;
  } else {
    cerr << 2 << endl;
    for (int i = 0; i < n1.size(); i++) {
      for (int j = 0; j < n3.size(); j++) {
        if (n3[j] == n1[i]) {
          c1++;
          break;
        }
      }
    }
    cerr << c1 << endl;
    for (int i = 0; i < n2.size(); i++) {
      for (int j = 0; j < n3.size(); j++) {
        if (n3[j] == n2[i]) {
          c2++;
          break;
        }
      }
    }
    cerr << c2 << endl;
    if ((c1 + c2) == n3.size()) {
      cerr << 2.1 << endl;
      cout << "YES";
    } else {
      cerr << 2.2 << endl;
      cout << "NO" << endl;
    }
  }
  return 0;
}
