#include <bits/stdc++.h>
using namespace std;
const int MAX = 100000;
const int INF = 1000000001;
int n;
int main(int argc, char *argv[]) {
  string a, b, c;
  cin >> a >> b >> c;
  a += b;
  sort((a).begin(), (a).end());
  sort((c).begin(), (c).end());
  if (a == c)
    cout << "YES" << endl;
  else
    cout << "NO" << endl;
  return 0;
}
