program Kvardat;
uses crt,graph;
var drajver,rezim,pom:integer;
    a,a0,x,y,x1,x2,y1,y2,x11:integer;
begin
  ClrScr;
  write(' Unesi duzinu stranice kvadrata : ');
  readln(a);
  a0:=a*5;
  initgraph(drajver,rezim,'');
  if (a0>0) and (a0<(GetMaxY div 2))
    then
    begin
      x:=(GetMaxX+1) div 2;
      y:=(GetMaxY+1) div 2;
      x1:=x-a0;
      y1:=y-a0;
      x2:=x+a0;
      y2:=y+a0;
      rectangle(x1,y1,x2,y2);
      readln;
      closegraph
    end
    else
    begin
      write(' Kvadrat se za datu duzinu ne vidi, a je u [0,',GetMaxY div 5,']!');
      readln
    end
end.