/in/foo.cc: In function 'int main()':
/in/foo.cc:10:17: warning: unused variable 'now' [-Wunused-variable]
     int n,i,j,k,now,nx,ans=0;
                 ^~~
/in/foo.cc:10:21: warning: unused variable 'nx' [-Wunused-variable]
     int n,i,j,k,now,nx,ans=0;
                     ^~