y = tonumber(63)
ystart = y
for i = 0, 2, 1 do
if not turtle.detectDown() then
turtle.down()
y = y-1
i = i-1
end
end
yend = y
for u=yend, ystart, 1 do
turtle.up()
y = y 1
turtle.placeDown()
end
print("lowest level: "..yend)