#include <bits/stdc++.h>
using namespace std;
int main() {
  string a, b, c, d;
  cin >> a;
  cin >> b;
  cin >> c;
  d = a + b;
  sort(d.begin(), d.end());
  sort(c.begin(), c.end());
  if (d == c) {
    cout << "YES" << endl;
  } else {
    cout << "NO" << endl;
  }
  return 0;
}
