#include <bits/stdc++.h>
using namespace std;
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  char a[105], b[105], c[105];
  int l1, l2, flag = 0;
  cin.getline(a, 105);
  cin.getline(b, 105);
  cin.getline(c, 105);
  strcat(b, a);
  l1 = strlen(b);
  l2 = strlen(c);
  multiset<char> m1(b, b + l1);
  multiset<char> m2(c, c + l2);
  multiset<char>::iterator it1, it2;
  if (m1.size() == m2.size()) {
    for (it1 = m1.begin(), it2 = m2.begin(); it1 != m1.end(); it1++, it2++) {
      if (*it1 != *it2) {
        flag = 1;
        break;
      }
    }
  } else {
    flag = 1;
  }
  if (flag == 0)
    cout << "YES" << endl;
  else
    cout << "NO" << endl;
  return 0;
}
