
int main() {
  int n;
  char buf[1024];
  char *tmp;
  int i;
  int ok;
  scanf("%d", &n);
  for (i = 0; i < n; ++i) {
    scanf("%s", buf);
    ok = 1;
    tmp = buf;
    if (isdigit(*tmp)) {
      ok = 0;
    } else {
      while (*tmp != 0) {
        if (!isalnum(*tmp) && *tmp != '_') {
          ok = 0;
          break;
        }
        ++tmp;
      }
    }
    if (ok == 1)
      printf("yes\n");
    else
      printf("no\n");
  }
  return 0;
}