/in/foo.cc: In function 'int main()':
/in/foo.cc:20:18: warning: format '%d' expects argument of type 'int', but argument 2 has type 'long long int' [-Wformat=]
   printf("%d",sum);
                  ^
/in/foo.cc:8:8: warning: 'k' is used uninitialized in this function [-Wuninitialized]
 while(k>0)
       ~^~