/in/foo.cc: In function 'bool check()':
/in/foo.cc:52:14: warning: variable 'y2' set but not used [-Wunused-but-set-variable]
     int x2=0,y2=0,x3=0,y3=0;
              ^~
/in/foo.cc:52:24: warning: variable 'y3' set but not used [-Wunused-but-set-variable]
     int x2=0,y2=0,x3=0,y3=0;
                        ^~