local arg = {...}
local tunnelDistance = 1
local traveled = 0
if arg[1] then
    tunnelDistance = tonumber(arg[1])
else
    while true do
        term.write("How long should I tunnel for?")
        tunnelDistance = tonumber(read())
        if tunnelDistance then
            break
        end
        print("Cannot Compute")
    end
end
while true do
    if not turtle.detect() then
        turtle.forward()
        traveled = traveled + 1
    else
        break
    end
end
if tunnelDistance == 1 then
    tunnelDistance = 2
end
shell.run("tunnel", tunnelDistance + 1)
shell.run("turn", "right", "2")
shell.run("go","forward",  tunnelDistance + traveled )
shell.run("turn", "right", "2")