/in/foo.cc: In function 'int main()':
/in/foo.cc:60:11: warning: unused variable 'u' [-Wunused-variable]
   int x,k,u,t;scanf("%d %d",&x,&k);
           ^
/in/foo.cc:60:13: warning: unused variable 't' [-Wunused-variable]
   int x,k,u,t;scanf("%d %d",&x,&k);
             ^