text: #include <stdio.h>
  #include <stdlib.h>
  
  bool uniqueCharacters(char str[]) {
      int map[128] = {0}, curr = 0;
      while (str[curr]) {
          if (map[(str[curr])]) return false;
          else map[(str[curr])] = 1;
          curr++;
      }
      return true;
  }
  
  int main(void) {
      int T;
      char str[1000];
      scanf("%d\n", & T);
      while (T--) {
          scanf("%s\n", str);
          if (uniqueCharacters(str)) printf("yes\n");
          else printf("no\n");
      }
      return 0;
  }