flog2

local offset = 0

local function fellTree()
  turtle.dig()
  turtle.forward()
  local height = 0
  while ( turtle.detectUp() ) do
    turtle.dig()
    turtle.digUp()
    turtle.up()
    height = height + 1
  end

  turtle.turnRight()
  turtle.dig()
  turtle.forward()
  turtle.turnLeft()

  for i=1,height do
    turtle.dig()
    turtle.digDown()
    turtle.down()
  end
  turtle.dig()
end

local function plant()
  turtle.up()
  turtle.select(2)
  for i=1,4 do
    turtle.suckDown()
    turtle.placeDown()
    turtle.forward()
    turtle.turnLeft()
  end
end

local function moveToSuck()
  turtle.turnLeft()
  turtle.forward()
  turtle.turnLeft()
  turtle.forward()
  turtle.forward()
  turtle.turnLeft()
  turtle.down()
end

local function moveFromSuck()
  turtle.turnLeft()
  turtle.forward()
end

local function suckWalk(dist)
  for i=1,dist do
    turtle.suck()
    turtle.turnRight()
    turtle.suck()
    turtle.turnLeft()
    turtle.turnLeft()
    turtle.suck()
    turtle.turnRight()
    turtle.forward()
  end
end

local function suckRound()
  for i=1,4 do
    suckWalk(3)
    turtle.turnLeft()
    suckWalk(2)
  end
end

local function findNextTree()
  turtle.up()
  turtle.select(1)
  turtle.turnRight()
  for i=1,10 do
    turtle.forward()
    offset = offset + 1
    turtle.turnLeft()
    if turtle.detect() then
      turtle.down()
      return true
    else
      turtle.turnRight()
    end
  end
  turtle.down()
  return false
end

local function returnToStart()
  turtle.turnLeft()
  turtle.turnLeft()
  while (offset > 0) do
    turtle.forward()
    offset = offset - 1
  end
  turtle.turnRight()
end

while (findNextTree()) do
  fellTree()
  plant()
  moveToSuck()
  suckRound()
  moveFromSuck()
end
returnToStart()