/in/foo.cc: In function 'int main()':
/in/foo.cc:8:10: warning: unused variable 't' [-Wunused-variable]
  int n,k,t,tmp,tmp2,alive=0,ans=0;
          ^
/in/foo.cc:8:21: warning: unused variable 'alive' [-Wunused-variable]
  int n,k,t,tmp,tmp2,alive=0,ans=0;
                     ^~~~~