function go()
   for i = 1, 4 do
      for i= 1, 5 do
      tunnel()
      end
   torch()
   end
end

function forward()
   while not turtle.forward() do
   turtle.dig()
   end
end

function up()
   while not turtle.up() do
   turtle.digUp()
   end
end

function down()
   while not turtle.down() do
   turtle.digDown()
   end
end



function replacef()
   while not turtle.place() do
   turtle.dig()
   end
end

function replaceu()
   while not turtle.placeUp() do
   turtle.digUp()
   end
end

function replaced()
   while not turtle.placeDown() do
   turtle.digDown()
   end
end


function tl()
turtle.turnLeft()
end

function tr()
turtle.turnRight()
end

function torch()
turtle.select(9)
tl()
forward()
replacef()
turtle.select(1)
tr()
tr()
forward()
tl()
end

function tunnel()
forward()
turtle.digUp()
replaced()
tl()
forward()
replaced()
replacef()
up()
replacef()
up()
replaceu()
tr()
tr()
forward()
replaceu()
forward()
replaceu()
replacef()
down()
replacef()
down()
replacef()
tl()
tl()
replaced()
forward()
tr()
end

go()