/in/foo.cc: In function 'int main()':
/in/foo.cc:5:14: warning: unused variable 'k' [-Wunused-variable]
  int n,m,s=1,k=1,x=0,y=1;
              ^
/in/foo.cc:5:22: warning: unused variable 'y' [-Wunused-variable]
  int n,m,s=1,k=1,x=0,y=1;
                      ^