Program P1;
uses
Graph,Crt;
var
d,m,i,k : integer;
x,y,x0,y0,r : integer;
a,b : real;
begin

d := detect;

InitGraph(d,m,'');

x0 := 640 div 2;
y0 := 480 div 2;

i := 1;

r := 100;

a := 0;
b := 1;

x := x0;
y := y0;

repeat

Delay(100);

a := a + 0.1;
b := b - 0.1;

ClearDevice;

Circle(x0,y0,r);

x := round(x0 + (r+20)*cos(a));
y := round(y0 + (r+20)*sin(a));

putpixel(x,y,65535);

x := round(x0 + (r+40)*cos(b));
y := round(y0 + (r+40)*sin(b));

putpixel(x,y,65535);

until
KeyPressed = true;

CloseGraph;

end.