uses crt,graph;
label 1;
var a,b,x,y,xv,yv,xn,yn,xv2,yv2,xn2,yn2:integer;
    c:char;
begin
Randomize;
a:=detect;
Initgraph(a,b,'');
Setcolor(2);
line(50,150,50,200);
line(75,225,125,225);
line(150,200,150,150);
line(100,225,100,300);
line(75,300,125,300);
line(50,200,75,225);
line(150,200,125,225);
line(75,300,50,325);
line(50,325,150,325);
line(150,325,125,300);
line(125,300,100,325);
setfillstyle(1,2);
floodfill(100,310,2);
setfillstyle(1,2);
floodfill(125,310,2);
1:x:=0;
y:=0;
xv:=100;
yv:=100;
xn:=100;
yn:=200;
xv2:=100;
yv2:=150;
xn2:=100;
yn2:=150;
repeat
setcolor(5);
line(xv,yv,x+50,y+150);
line(xv,yv,x+150,y+150);
line(xn,yn,x+50,y+150);
line(xn,yn,x+150,y+150);

line(xv2,yv2,x+50,y+150);
line(xv2,yv2,x+150,y+150);
line(xn2,yn2,x+50,y+150);
line(xn2,yn2,x+150,y+150);
delay(3000);
setcolor(0);
line(xv,yv,x+50,y+150);
line(xv,yv,x+150,y+150);
line(xn,yn,x+50,y+150);
line(xn,yn,x+150,y+150);

line(xv2,yv2,x+50,y+150);
line(xv2,yv2,x+150,y+150);
line(xn2,yn2,x+50,y+150);
line(xn2,yn2,x+150,y+150);
yv:=yv+1;
yn:=yn-1;
yn2:=yn2+1;
yv2:=yv2-1;
until  yn2=200;
goto 1;
closegraph;
end.