#include <bits/stdc++.h>
int main() {
  int i, len, len2, j, count = 0;
  char s1[1000], s2[1000], s3[200], s4[200];
  scanf("%s %s %s", s1, s2, s3);
  strcat(s1, s2);
  len = strlen(s1);
  len2 = strlen(s3);
  if (len == len2) {
    for (i = 0; i < len; i++) {
      for (j = 0; j < len2; j++) {
        if (s1[i] == s3[j]) {
          count++;
          s3[j] = i - 456473;
          break;
        }
      }
    }
  } else {
    printf("NO");
    return 0;
  }
  if (count == len) {
    printf("YES");
  } else {
    printf("NO");
  }
  return 0;
}
