/in/foo.cc: In function 'int main()':
/in/foo.cc:26:17: error: expected ',' or ';' before 'for'
   26 |                 for (int i=2;i*i<=b[i];i++)
      |                 ^~~
/in/foo.cc:26:33: warning: statement has no effect [-Wunused-value]
   26 |                 for (int i=2;i*i<=b[i];i++)
      |                              ~~~^~~~~~
/in/foo.cc:26:43: error: expected ';' before ')' token
   26 |                 for (int i=2;i*i<=b[i];i++)
      |                                           ^
      |                                           ;