Помогите с Pascal ABC квадратная спираль

Wrap enabled uses Graph; const delta: array[1 .. 4] of record X, Y: integer; end = ((X:-1; Y: 0), (X: 0; Y:-1), (X: 1; Y: 0), (X: 0; Y: 1)); var grDriver, grMode, ErrCode: Integer; len, i, j: integer; begin grDriver := Detect; InitGraph(grDriver, grMode,''); ErrCode := GraphResult; if ErrCode <> grOk then begin Writeln('Graphics error:', GraphErrorMsg(ErrCode)); readln; halt end; len := 10; moveto(getmaxx div 2, getmaxy div 2); for i := 1 to 10 do begin for j := 1 to 2 do linerel(delta[j].X*len, delta[j].Y*len); inc(len, 10); for j := 3 to 4 do linerel(delta[j].X*len, delta[j].Y*len); inc(len, 10) end; readln; closegraph; end. Примерно