/in/foo.cc: In function 'int main()':
/in/foo.cc:79:8: warning: unused variable 'y' [-Wunused-variable]
  int x,y,z,k;
        ^
/in/foo.cc:79:10: warning: unused variable 'z' [-Wunused-variable]
  int x,y,z,k;
          ^
/in/foo.cc:79:12: warning: unused variable 'k' [-Wunused-variable]
  int x,y,z,k;
            ^