/in/foo.cc: In function 'int main()':
/in/foo.cc:5:12: warning: unused variable 's' [-Wunused-variable]
  int n,p,k,s=0,z=0;
            ^
/in/foo.cc:5:16: warning: variable 'z' set but not used [-Wunused-but-set-variable]
  int n,p,k,s=0,z=0;
                ^