#include <bits/stdc++.h>
using namespace std;
int main() {
  char s[3][100];
  int a[26];
  memset(a, 0, sizeof(a));
  for (int i = 0; i < 3; i++) cin >> s[i];
  int l1 = strlen(s[0]) + strlen(s[1]);
  int l2 = strlen(s[2]);
  if (l2 != l1)
    cout << "NO"
         << "\n";
  else {
    for (int i = 0; i < strlen(s[0]); i++) {
      (a[s[0][i] - 'A'])++;
    }
    for (int i = 0; i < strlen(s[1]); i++) (a[s[1][i] - 'A'])++;
    for (int i = 0; i < l2; i++) (a[s[2][i] - 'A'])--;
    int cnt = 0;
    for (int i = 0; i < 26; i++) {
      if (a[i] != 0)
        break;
      else
        cnt++;
    }
    if (cnt == 26)
      cout << "YES"
           << "\n";
    else
      cout << "NO"
           << "\n";
  }
}
