#include <bits/stdc++.h>
using namespace std;
int main() {
  string s1, s2, s3;
  cin >> s1;
  cin >> s2;
  cin >> s3;
  int i, flag;
  int a[150], b[150];
  for (i = 0; i < 150; i++) {
    a[i] = 0;
    b[i] = 0;
  }
  for (i = 0; i < s1.length(); i++) {
    a[s1[i]]++;
  }
  for (i = 0; i < s2.length(); i++) {
    a[s2[i]]++;
  }
  for (i = 0; i < s3.length(); i++) {
    b[s3[i]]++;
  }
  flag = 0;
  for (i = 0; i < 150; i++) {
    if (a[i] != b[i]) {
      flag = 1;
      break;
    }
  }
  if (flag == 0)
    cout << "YES" << endl;
  else
    cout << "NO" << endl;
  return 0;
}
