klasika.c: In function 'append':
klasika.c:13:33: warning: suggest parentheses around '-' in operand of '&' [-Wparentheses]
   13 |  if (o == 0 || o >= 2 && (o & o - 1) == 0)
      |                               ~~^~~
klasika.c:13:23: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
   13 |  if (o == 0 || o >= 2 && (o & o - 1) == 0)
      |                ~~~~~~~^~~~~~~~~~~~~~~~~~~
klasika.c: In function 'main':
klasika.c:34:2: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   34 |  scanf("%d", &q);
      |  ^~~~~~~~~~~~~~~
klasika.c:40:3: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   40 |   scanf("%s%d", s, &i), i--;
      |   ^~~~~~~~~~~~~~~~~~~~
klasika.c:43:4: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   43 |    scanf("%d", &aa[j]), aa[j] ^= aa[i];
      |    ^~~~~~~~~~~~~~~~~~~
klasika.c:46:4: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   46 |    scanf("%d", &j), j--;
      |    ^~~~~~~~~~~~~~~