/in/foo.cc: In function 'll solve(ll&, int)':
/in/foo.cc:11:1: warning: no return statement in function returning non-void [-Wreturn-type]
 }
 ^
/in/foo.cc: In function 'int main()':
/in/foo.cc:19:20: warning: format '%d' expects argument of type 'int', but argument 2 has type 'll {aka long long int}' [-Wformat=]
   printf("%d\n",ans);
                    ^