#include <bits/stdc++.h>
using namespace std;
int main() {
  ios::sync_with_stdio(false), cin.tie(0), cout.tie(0);
  string s, s1, s2, res;
  cin >> s >> s1 >> s2;
  res = s + s1;
  sort(res.begin(), res.end());
  sort(s2.begin(), s2.end());
  if (res == s2) {
    printf("YES\n");
    return 0;
  }
  printf("NO\n");
  return 0;
}
