#include <bits/stdc++.h>
using namespace std;
string second, st, stt;
int j, k;
int main() {
  cin >> second >> st >> stt;
  for (int i = stt.size(); i >= 0; i--) {
    for (int j = second.size(); j >= 0; j--)
      if (second[j] == stt[i]) {
        second.erase(j, 1);
        stt.erase(i, 1);
      }
    for (int j = st.size(); j >= 0; j--)
      if (st[j] == stt[i]) {
        st.erase(j, 1);
        stt.erase(i, 1);
      }
  }
  if (second.size() == 0 && stt.size() == 0 && st.size() == 0)
    cout << "YES";
  else
    cout << "NO";
  return 0;
}
