#include <bits/stdc++.h>
using namespace std;
int main() {
  vector<char> w, e;
  string a, b, c;
  cin >> a >> b >> c;
  for (int i = 0; i < a.length(); i++) w.push_back(a[i]);
  for (int i = 0; i < b.length(); i++) w.push_back(b[i]);
  for (int i = 0; i < c.length(); i++) e.push_back(c[i]);
  sort(w.begin(), w.end());
  sort(e.begin(), e.end());
  if (w.size() != e.size())
    cout << "NO";
  else {
    for (int i = 0; i < w.size(); i++) {
      if (w[i] != e[i]) {
        cout << "NO";
        return 0;
      } else {
        if (i == w.size() - 1) cout << "YES";
      }
    }
  }
  return 0;
}
