process Trees and Champs

local function do_forward()
    while not turtle.forward() do
        if not turtle.dig() then
            turtle.attack()
        end
    end
end

local function do_up()
    while not turtle.up() do
        if not turtle.digUp() then
            turtle.attackUp()
        end
    end
end

local function do_down()
    while not turtle.down() do
        if not turtle.digDown() then
            turtle.attackDown()
        end
    end
end

local function go_elevator()
    do_forward()
    turtle.turnRight()
    for i = 1,3 do
        do_forward()
    end
    turtle.turnLeft()
end
local function go_home()
    turtle.turnLeft()
    turtle.turnLeft()
    do_forward()
    turtle.turnRight()
    for i = 1,3 do
        do_forward()
    end
    turtle.turnRight()
end

local level = 0
local function go_level(i)
    if level == 0 and i > 0 then
        for i = 1,(5+4*i) do
            do_up()
        end
    elseif i == 0 and level > 0 then
        for i = 1,(5+4*level) do
            do_down()
        end
    elseif level > i then
        for i = 1,(4*(level-i)) do
            do_down()
        end
    else
        for i = 1,(4*(i-level)) do
            do_up()
        end
    end

    level = i
end

local function do_cycle(i)
    shell.run("trees.lua")
    go_elevator()
    go_level(4*i)
    do_forward()
    shell.run("champs.lua", 1, 24)
    level = 4*i-3
    turtle.back()
    go_level(0)
    go_home()
end

do_cycle(1)
do_cycle(2)
do_cycle(3)