t = turtle

function distanceInput()
    print("Input Distance")
    num = io.read()
    num = tonumber(num)
    return num
end
function fuel(distance)
    t.refuel()
end
function hole(distance)
    while distance > 0 do
        if t.detectDown() then
            t.digDown()
            t.down()
        else
            t.down()
        end
    distance = distance - 1
    end
end
function dforward()
    if t.detect() then
        t.dig()
        t.forward()
    else
        t.forward()
    end
end
function turn()
    t.turnRight()
end
function mineLayer()
    num = 3
    if mark then
        while num > 0 do
            dforward()
            turn()
            dforward()
            num = num - 1
        end
        dforward()
        turn()
        t.digUp()
        t.up()
    else
        while num > 0 do
            dforward()
            dforward()
            turn()
            num = num - 1
        end
        --dforward()--
        t.digUp()
        t.up()
    end
end
function mine(distance)
    mark = true
    dforward()
    turn()
    while distance > 0 do
        mineLayer(mark)
        distance = distance - 1
        mark = not mark
    end
end
function spiral()
    distance = distanceInput()
    fuel(distance)
    print("3x3 Spiral Initiated; No further input required")
    hole(distance)
    mine(distance)
end

spiral()