/in/foo.cc: In function 'int main()':
/in/foo.cc:12:20: warning: format '%d' expects argument of type 'int', but argument 2 has type 'long long int' [-Wformat=]
     printf("%d",ans);
                    ^
/in/foo.cc:5:12: warning: unused variable 'a' [-Wunused-variable]
  long long a,x,ans;
            ^