i=0
while i<100 do
    while(not turtle.forward()) do
    turtle.dig()
    os.sleep(1)
    end
turtle.digUp()
turtle.digDown()
i=i+1
end
turtle.turnLeft()
turtle.turnLeft()
while i>1 do
if (not turtle.forward()) then
    turtle.dig()
end
i = i-1
end