/in/foo.cc: In function 'int main()':
/in/foo.cc:14:20: warning: format '%lld' expects argument of type 'long long int*', but argument 2 has type 'int*' [-Wformat=]
     scanf("%lld",&k);
                  ~~^
/in/foo.cc:33:11: warning: 'ans' may be used uninitialized in this function [-Wmaybe-uninitialized]
     printf("%d",ans);
     ~~~~~~^~~~~~~~~~