stdout:

stderr:
/home/wangfiox/Documents/database/hidden_functional_c/sy/28_side_effect2.sy:33:30: warning: if statement has empty body [-Wempty-body]
        f(18, i) && f(19, i));
                             ^
/home/wangfiox/Documents/database/hidden_functional_c/sy/28_side_effect2.sy:33:30: note: put the semicolon on a separate line to silence this warning
/home/wangfiox/Documents/database/hidden_functional_c/sy/28_side_effect2.sy:41:30: warning: if statement has empty body [-Wempty-body]
        g(18, i) || g(19, i));
                             ^
/home/wangfiox/Documents/database/hidden_functional_c/sy/28_side_effect2.sy:41:30: note: put the semicolon on a separate line to silence this warning
/home/wangfiox/Documents/database/hidden_functional_c/sy/28_side_effect2.sy:51:7: warning: expression result unused [-Wunused-value]
  sum + ans;
  ~~~ ^ ~~~
/home/wangfiox/Documents/database/hidden_functional_c/sy/28_side_effect2.sy:54:7: warning: expression result unused [-Wunused-value]
  sum * ans;
  ~~~ ^ ~~~
/home/wangfiox/Documents/database/hidden_functional_c/sy/28_side_effect2.sy:57:7: warning: expression result unused [-Wunused-value]
  sum - ans;
  ~~~ ^ ~~~
5 warnings generated.