def kreski(L):
    while L>0:
        if L>5:
            turtle.down()
            turtle.forward (2)
            turtle.up()
            turtle.forward(1)
            turtle.down()
            turtle.forward (2)

            L=L-5
        else:
            turtle.down()
            turtle.forward (L)
            turtle.up()
            turtle.forward(L)
            L=0