#include <bits/stdc++.h>
using namespace std;
void sortString(string &str) { sort(str.begin(), str.end()); }
int main() {
  string a, b, c;
  cin >> a >> b >> c;
  int i;
  int count = 0;
  string d = a + b;
  sortString(d);
  sortString(c);
  if (d.length() != c.length()) {
    cout << "NO";
  } else {
    for (i = 0; i < d.length(); i++) {
      if (d[i] == c[i]) {
        count++;
      }
    }
    if (count == d.length()) {
      cout << "YES";
    } else {
      cout << "NO";
    }
  }
}
