t = turtle

i = 0
q = 0
a = true


while i < 25 do
    t.dig()
    t.digUp()
    t.digDown()
    t.forward()
    if i == 24 and a then
        t.turnLeft()
        t.dig()
        t.forward()
        t.turnLeft()
        i = 0
        a = false

    elseif i == 24 and not a then
        t.turnRight()
        t.dig()
        t.forward()
        t.turnRight()
        i = 0
        a = not a
    end
    i = i + 1
end