_PICKUPER

function IsChest()
    success, data = turtle.inspect()
    if not success then
        return false
    end
    if data.name == "minecraft:chest" then
        return true
    end
    return false
end

function dropoff()
    for n=1,16 do
        local nCount = turtle.getItemCount(n)
        if nCount > 0 then
            turtle.select(n)
            turtle.drop()
        end
    end
end

while true do
    if turtle.forward() then
        if turtle.detectDown() then
            turtle.digDown()
        end
    else
        if IsChest() then
            dropoff()
        end
        turtle.turnLeft()
    end
end