n = 50
--------------------------
function dig(n)
    for i=1,n do
        turtle.dig()
        turtle.digUp()
        turtle.digDown()
        turtle.forward()
    end
end
--------------------------
dig(n)
--------------------------
turtle.turnLeft()
turtle.dig()
turtle.digUp()
turtle.digDown()
turtle.forward()
turtle.turnLeft()
turtle.dig()
turtle.digUp()
turtle.digDown()
--------------------------
dig(n)
--------------------------
turtle.select(16)
turtle.place()
turtle.drop()