#include <bits/stdc++.h>
using namespace std;
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
  string s1, s2, s3;
  map<char, long long int> mp1, mp2;
  cin >> s1 >> s2 >> s3;
  set<char> st;
  for (auto i = 0; i < s1.size(); i++) {
    mp1[s1[i]]++;
    st.insert(s1[i]);
  }
  for (auto i = 0; i < s2.size(); i++) {
    mp1[s2[i]]++;
    st.insert(s2[i]);
  }
  for (auto i = 0; i < s3.size(); i++) {
    mp2[s3[i]]++;
  }
  long long int blb = 0;
  for (auto i : st) {
    if (mp1[i] != mp2[i]) {
      blb = 1;
      break;
    }
  }
  if (s3.size() > s1.size() + s2.size()) blb = 1;
  if (blb)
    cout << "NO\n";
  else
    cout << "YES\n";
  return 0;
}
