/in/foo.cc: In function 'int main()':
/in/foo.cc:131:17: warning: unused variable 'x' [-Wunused-variable]
         int u,v,x,y;
                 ^
/in/foo.cc:131:19: warning: unused variable 'y' [-Wunused-variable]
         int u,v,x,y;
                   ^