/in/foo.c:12:6: warning: return type of 'main' is not 'int' [-Wmain]
 void main()
      ^~~~
/in/foo.c: In function 'main':
/in/foo.c:18:13: error: expected ')' before 'gbs'
  printf(gys gbs);
             ^~~
/in/foo.c:18:9: warning: passing argument 1 of 'printf' makes pointer from integer without a cast [-Wint-conversion]
  printf(gys gbs);
         ^~~
In file included from /in/foo.c:1:0:
/usr/include/stdio.h:364:12: note: expected 'const char * restrict' but argument is of type 'int'
 extern int printf (const char *__restrict __format, ...);
            ^~~~~~
/in/foo.c:14:14: warning: variable 'gbs' set but not used [-Wunused-but-set-variable]
  int A,B,gys,gbs;
              ^~~