filler

s=1
turtle.turnLeft()
lft=turtle.detect()
turtle.turnRight()
if(lft==true) then
  ok=0
else
  ok=1
end
turtle.select(s)
turtle.back()

while true do
  pl=turtle.place()
  if(pl==true) then
    bk=turtle.back()
    if(bk==false and ok==0) then
      turtle.turnLeft()
      turtle.back()
      turtle.place()
      turtle.turnLeft()
      turtle.back()
      ok=1
    elseif(bk==false and ok==1) then
      turtle.turnRight()
      turtle.back()
      turtle.place()
      turtle.turnRight()
      turtle.back()
      ok=0
    end
    else
      s=s+1
      turtle.select(s)
      if(s==16) then
        turtle.place()
        for i=1,15 do
          turtle.select(i)
          turtle.suck()
        end
        s=1
        turtle.dig()
        turtle.select(s)
      end
  end
end