x = 0
y = 0
lookup = {4, 1, 3, 0, 2}
local function test()
    local val = lookup[(y % 5) + 1]
    return (x % 5) == val
end

local function run()
    for i = 1,3 do
        for j = 1,6 do
            turtle.forward()
            x = x + 1
            if test() then
                turtle.digDown()
            end
        end
        turtle.turnRight()
        turtle.forward()
        y = y + 1
            if test() then
                turtle.digDown()
            end
        turtle.turnRight()
        for j = 1,6 do
            turtle.forward()
            x = x - 1
            if test() then
                turtle.digDown()
            end
            if test() then
                turtle.digDown()
            end
        end
        turtle.turnLeft()
        turtle.forward()
        y = y + 1
            if test() then
                turtle.digDown()
            end
        turtle.turnLeft()
    end
end
run()