Исчезновение круга при соприкосновении с другим

uses GraphAbc;
const n=20;
type 
  rs=record
    x,y,dx,dy,r:integer;
    C:System.Drawing.Color;
    e:boolean;
  end;
var
  quit:boolean;
  sp:array[0..n] of rs;
  i:integer;
  B:System.Drawing.Color;
procedure dxdy(var dx,dy:integer;var c:System.Drawing.Color;b:System.Drawing.Color);
var
  tx,ty:integer;
begin
repeat
  tx:=random(3)-1;
  ty:=random(3)-1;
until ((tx<>0) or (ty<>0)) and (tx<>dx) and (ty<>dy);
dx:=tx;dy:=ty;
if c<>clWhite then repeat c:=clRandom; until (c<>b) and (c<>clwhite);
end;
procedure KeyUp(key:integer);
var
  tx,ty:integer;
begin
  tx:=0;
  ty:=0;
  case Key of
    VK_Up:ty:=-1;
    VK_Down:ty:=1;
    VK_Left:tx:=-1;
    VK_Right:tx:=1;
    VK_Escape:quit:=true;
    else exit;
  end;
  sp[0].dx:=tx;
  sp[0].dy:=ty;
end;  
begin
  quit:=false;
  OnKeyUp:=KeyUp;
  randomize;
  SetWindowHeight(480);
  SetWindowWidth(640);
  SetWindowIsFixedSize(true);
  b:=clGreen;
  SetBrushColor(b);
  SetPenColor(b);
  FillRectangle(0,0,WindowWidth,WindowHeight);
  for i:=0 to n do begin 
      sp[i].x:=random(WindowWidth-20)+10;
      sp[i].y:=random(WindowHeight-20)+10;
      sp[i].r:=random(10)+5;
      dxdy(sp[i].dx,sp[i].dy,sp[i].C,B);
      sp[i].e:=true;
  end;
  sp[0].C:=clWhite;
  sp[0].r:=10;
  repeat
    LockDrawing;
    for i:=0 to n do  if sp[i].e then begin 
      SetBrushColor(B);
      circle(sp[i].x,sp[i].y,sp[i].r);
      SetBrushColor(sp[i].C);
    if (sp[i].x+sp[i].dx>Window.Width-sp[i].r) or (sp[i].x+sp[i].dx<sp[i].r) 
    or (sp[i].y+sp[i].dy>WindowHeight-sp[i].r) or (sp[i].y+sp[i].dy<sp[i].r) then dxdy(sp[i].dx,sp[i].dy,sp[i].c,b)
    else begin  
      sp[i].x:=sp[i].x+sp[i].dx;
      sp[i].y:=sp[i].y+sp[i].dy;
      if (i>0) and (sqrt(sqr(sp[i].x-sp[0].x)+sqr(sp[i].y-sp[0].y))<=sp[i].r+sp[0].r) then begin
        sp[i].e:=false;sp[0].r:=sp[0].r+1; 
      end
        else
      Circle(sp[i].x,sp[i].y,sp[i].r);
    end;
  end;  
    UnlockDrawing;
  until quit;
  Window.close;
end.

program agario;
 
uses GraphABC;
var
  x, y, r, xb, yb, rb, x1, x2, x3, x4, x5, y1, y2, y3, y4, y5: integer;
  z: char;c, a: color;
 
procedure GameMenu();
begin
  SetWindowWidth(1000);
  SetWindowHeight(500);
  ClearWindow(clBlue);
  Rectangle(400, 10, 600, 400);
  FloodFill(450, 20, clWhite);
  SetPenWidth(1);
  TextOut(420, 20, 'Добро пожаловать!');
  SetPenWidth(3);
  TextOut(410, 190, 'Для начала введите start: ');
  SetPenWidth(1);
end;
 
procedure move(x, y, r: integer);
begin
  SetPenWidth(1);
  Brush.Color := c;
  Circle(x, y, r);
end;
 
procedure KeyDown(key: integer);
begin
  case key of
    VK_W, VK_Up:
      begin
        LockDrawing;
        SetPenColor(clWhite); SetPenWidth(3); Brush.Color := clWhite; Circle(x, y, r); SetPenColor(clBlack);y := y - 10; move(x, y, r);
        Redraw;  end;
    VK_D, VK_Right:
      begin
        LockDrawing;
        SetPenColor(clWhite); SetPenWidth(3); Brush.Color := clWhite; Circle(x, y, r); SetPenColor(clBlack);x := x + 10; move(x, y, r);
        REdraw; end;
    VK_S, VK_Down:
      begin
        LockDrawing; 
        SetPenColor(clWhite); SetPenWidth(3); Brush.Color := clWhite; Circle(x, y, r); SetPenColor(clBlack);y := y + 10; move(x, y, r);
        Redraw; end;
    VK_A, VK_Left:
      begin
        LockDrawing; 
        SetPenColor(clWhite); SetPenWidth(3); Brush.Color := clWhite; Circle(x, y, r); SetPenColor(clBlack);x := x - 10; move(x, y, r);
        REdraw; end;
  end;
end;
 
procedure Game(x1, x2, x3, x4, x5, y1, y2, y3, y4, y5: integer);
begin
  Brush.Color := clRandom;
  Circle(x1, y1, 5);
  Brush.Color := clRandom;
  Circle(x2, y2, 5);
  Brush.Color := clRandom;
  Circle(x3, y3, 5);
  Brush.Color := clRandom;
  Circle(x4, y4, 5);
  Brush.Color := clRandom;
  Circle(x5, y5, 5);
  if (r+5=Sqrt((x-x1)+(y-y1))) then
  ClearWindow;
end;
 
begin
  randomize;
  x1 := random(999) + 1;y1 := random(499) + 1;
  x2 := random(999) + 1;y2 := random(499) + 1;
  x3 := random(999) + 1;y3 := random(499) + 1;
  x4 := random(999) + 1;y4 := random(499) + 1;
  x5 := random(999) + 1;y5 := random(499) + 1;
  c := clrandom;
  r := 10;
  x := random(999) + 1;
  y := random(499) + 1;
  GameMenu;
  Readln(z);
  if z = 'S' then
  begin
    window.Clear;
    Game(x1, x2, x3, x4, x5, y1, y2, y3, y4, y5);
    Brush.Color := c;
    Circle(x, y, r);
    OnKeyDown := KeyDown;
  end
  else
  if z = 's' then
  begin
    window.Clear;
    Game(x1, x2, x3, x4, x5, y1, y2, y3, y4, y5);
    Brush.Color := c;
    Circle(x, y, r);
    OnKeyDown := KeyDown;
  end
else
  
end.