#include <bits/stdc++.h>
using namespace std;
string s, s1, s2;
int main() {
  cin >> s >> s1 >> s2;
  for (int i = 0; i < s.length(); i++) s1.push_back(s[i]);
  for (int i = s1.length() - 1; i >= 0; i--)
    for (int j = 0; j < s2.length(); j++)
      if (s1[i] == s2[j]) {
        s1.erase(s1.begin() + i);
        s2.erase(s2.begin() + j);
      }
  if (s1.length() == 0 && s2.length() == 0)
    cout << "YES";
  else
    cout << "NO";
  return 0;
}
