#include <bits/stdc++.h>
using namespace std;
int main() {
  char name1[102], name2[102], name3[102];
  int l1, l2, c = 0;
  cin >> name1 >> name2 >> name3;
  strcat(name1, name2);
  l1 = strlen(name1);
  l2 = strlen(name3);
  sort(name1, name1 + l1);
  sort(name3, name3 + l2);
  if (l1 != l2) {
    cout << "NO" << endl;
    return 0;
  } else
    for (int i = 0; i < l1; i++) {
      if (name1[i] == name3[i]) c++;
    }
  if (c == l1)
    cout << "YES" << endl;
  else
    cout << "NO" << endl;
  return 0;
}
