local n = 3
function kaitenbori(down)
local count = 0
for i = 1, down do
local result = turtle.digDown()
if result == true then
count = count + 1
else
break
end
turtle.down()
for i = 1, 4 do
turtle.turnLeft()
turtle.dig()
end
end
return count - 1
end

function backToHome(up)
for i = 1, up do

turtle.up()

end
end

turtle.select(1)
turtle.refuel()
local up = kaitenbori(n)
backToHome(up)

for j = 1, 4 do
turtle.place()
turtle.turnLeft()
end

turtle.up()
turtle.placeDown()