for i=1,3 do
    turtle.refuel(1)
end
function ligne()
    for i=1,25 do
        turtle.dig()
        turtle.forward()
    end
    for i=1,25 do
        turtle.back()
        turtle.select(2)
        turtle.place()
    end
end
ligne()
turtle.up()
ligne()
turtle.up()
ligne()
turtle.down()
turtle.down()