local lastPlayername = ""
local levelHeight = 6

local shaftBox {
    min = {x = -744, z = 1474},
    max = {x = -748, z = 1470},
}

local hallwayBox {
    min = {x = -749, z = 1470},
    max = {x = -744, z = 1477},
}

local level = {
    MOUNTAIN = 1,
    ALLEY = 0,
    ENCHANT = -1,
    OREPROCESSING = -2,
    AUTOCRAFTING = -3,
    CHICKENS = -4,
    SPAWNER = -10,
    REACTOR = -11,
}

local playerDetector = peripheral.wrap("left")


local function main_loop()
    if lastPlayername == "":