tunel

local inicio
if turtle.getFuelLevel() ~= "unlimited" and turtle.getFuelLevel() < 1 then
    turtle.refuel()
end
print("longitud?")
num1 = read()
print("ancho?")
ancho = read()
print("alto (>=3)?")
alto = read() - 2
if alto < 1 then
    alto = 1
end
--inicio = 0
--inicio2 = 0
--inicio3 = 0
--print("num1: "..num1)
--print("ancho: "..ancho)
--print("alto: "..alto)

for inicio=1,alto do
    for inicio2=1,ancho do
        for inicio3=1,num1 do
            turtle.dig()
            turtle.forward()
            turtle.digDown()
            turtle.digUp()
            --inicio3 = inicio3 + 1
            --print("inicio3: "..inicio3)
        end
            --inicio2=inicio2+1
        resto = inicio2 % 2
        if inicio2 ~= ancho then
         if resto == 0 then
            turtle.dig()
            turtle.forward()
            turtle.digDown()
            turtle.digUp()
            turtle.turnRight()
            turtle.dig()
            turtle.forward()
            turtle.digDown()
            turtle.digUp()
            turtle.turnRight()
            --inicio2 = inicio2 + 1
         else
            turtle.dig()
            turtle.forward()
            turtle.digDown()
            turtle.digUp()
            turtle.turnLeft()
            turtle.dig()
            turtle.forward()
            turtle.digDown()
            turtle.digUp()
            turtle.turnLeft()
            --inicio2 = inicio2 + 1
         end
        end
    end
    --inicio=inicio+1
    resto = ancho % 2
    if resto == 0 then
        --turtle.dig()
        turtle.forward()
        turtle.turnLeft()
        j = ancho - 1
        for i=0,j do
            turtle.forward()
        end
        turtle.turnLeft()
    else
        --turtle.dig()
        turtle.turnRight()
        turtle.turnRight()
        for i=0,num1 do
            turtle.forward()
        end
        j = ancho - 1
        for i=0,j do
            turtle.forward()
        end
        turtle.turnLeft()
    end
    x = alto-inicio
    if x==1 then
        turtle.up()
        turtle.digUp()
    elseif x==2 then
        turtle.up()
        turtle.digUp()
        turtle.up()
        turtle.digUp()
        inicio = inicio + 1
    elseif x==3 then
        turtle.up()
        turtle.digUp()
        turtle.up()
        turtle.digUp()
        turtle.up()
        turtle.digUp()
        inicio = inicio + 2
    end
end
for i=2,alto do
    turtle.down ()
end