local function digFwd()
        digFwdNoDeposit()
        checkDeposit()
    end
    local function digFwdNoDeposit()
        if not turtle.dig() do error("dig fail") end
    end
    local function digDown()
        digDownNoDeposit()
        checkDeposit()
    end
    local function digDownNoDeposit()
        if not turtle.digDown() do error("dig fail") end
    end
    local function checkDeposit()
        local item_count = turtle.getItemCount(14)
        if item_count > 0 then
            depositNow()
        end
    end
    local function depositNow()
        local chest_count = turtle.getItemCount(16)
        if item_count <= 0 then
            error("no chests")
        end
        turtle.select(16)
        turtle.turnRight()
        turtle.turnRight()
        digDownNoDeposit()
        turtle.place()
        for j=1,14 do
            turtle.transferTo(j)
        end
        turtle.turnRight()
        turtle.turnRight()
    end
    local forward_dist = 20
    local right_dist_over_two = 10
    while true do
        for j=1,right_dist_over_two do
            for i=1,forward_dist do
                digFwd()
                turtle.forward()
            end
            turtle.turnRight()
            digFwd()
            turtle.forward()
            turtle.turnRight()
            for i=1,forward_dist do
                digFwd()
                turtle.forward()
            end
            turtle.turnLeft()
            digFwd()
            turtle.forward()
            turtle.turnLeft()
        end
        depositNow()
        turtle.turnLeft()
        digDownNoDeposit()
        turtle.down()
        for j=1,right_dist_over_two * 2 do
            digFwdNoDeposit()
            turtle.forward()
        end
        turtle.turnRight()
    end