/in/foo.cc: In function 'int main()':
/in/foo.cc:37:7: warning: unused variable 'x' [-Wunused-variable]
   int x;
       ^
/in/foo.cc:39:7: warning: unused variable 'y' [-Wunused-variable]
   int y;
       ^
/in/foo.cc:41:7: warning: unused variable 'z' [-Wunused-variable]
   int z;
       ^