/in/foo.c: In function 'main':
/in/foo.c:9:24: error: 'arr' undeclared (first use in this function)
         scanf("%d%d", &arr[i], &brr[i]);
                        ^~~
/in/foo.c:9:24: note: each undeclared identifier is reported only once for each function it appears in
/in/foo.c:9:33: error: 'brr' undeclared (first use in this function)
         scanf("%d%d", &arr[i], &brr[i]);
                                 ^~~
/in/foo.c:12:5: warning: suggest parentheses around assignment used as truth value [-Wparentheses]
     if(N=6)
     ^~
/in/foo.c:15:3: warning: suggest parentheses around assignment used as truth value [-Wparentheses]
   if(N=9)
   ^~
/in/foo.c:18:14: warning: passing argument 1 of 'printf' makes pointer from integer without a cast [-Wint-conversion]
       printf(N*4);
              ^
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:5:9: warning: unused variable 'max' [-Wunused-variable]
     int max=0;
         ^~~