/in/foo.cc: In function 'int main()':
/in/foo.cc:17:27: error: 'a' cannot be used as a function
   17 |                          a(j+1)=j;
      |                          ~^~~~~
/in/foo.cc:13:27: warning: suggest explicit braces to avoid ambiguous 'else' [-Wdangling-else]
   13 |                         if(x%j==0)
      |                           ^