/in/foo.c: In function 'main':
/in/foo.c:5:21: warning: unused variable 'y3' [-Wunused-variable]
     int x1,x2,y1,y2,y3;
                     ^~
/in/foo.c:5:18: warning: unused variable 'y2' [-Wunused-variable]
     int x1,x2,y1,y2,y3;
                  ^~
/in/foo.c:5:15: warning: unused variable 'y1' [-Wunused-variable]
     int x1,x2,y1,y2,y3;
               ^~