Text Tunnel

local spin = 50
local cut = 9
local left = ""
local right = ""
local direction = true
local start = ""
local finish
for j = 1, cut - 3 do
    start = start .. " "
end
print(start .. "start")
for i = 1, 100 do
    for j = 1, cut - 1 do
        left = left .. "-"
    end
    for j = 1, spin - cut do
        right = right .. "-"
    end
    print(left .. " " .. right)
    left = ""
    right = ""
    if direction == true then
        cut = cut + 1
    elseif direction == false then
        cut = cut - 1
    end
    if cut == spin - 1 and direction == true then
        direction = false
    elseif cut == 2 and direction == false then
        direction = true
    end
    finish = ""
    for j = 1, cut - 3 do
        finish = finish .. " "
    end
end
print(finish .. "finish")