1x1 tree

function checkFuel()
    if turtle.getFuelLevel() < 100 then
        turtle.select(1)
        turtle.refuel(1)
    end
end

function getWood()
    y=0
    turtle.select(4)
    for i=1,10 do
        turtle.dig()
        turtle.digUp()
        turtle.up()
    end
    for i=1, 10 do
        turtle.down()
    end
end

function drop()
    x=4
    for i=1, 11 do
        turtle.select(x)
        turtle.dropDown()
        x=x+1
    end
end

function supply()
    turtle.turnLeft()
    turtle.select(1)
    turtle.suck()
    turtle.select(4)
    turtle.drop()

    turtle.turnLeft()
    turtle.select(2)
    turtle.suck()
    turtle.select(4)
    turtle.drop()

    turtle.turnLeft()
    turtle.select(3)
    turtle.suck()
    turtle.select(4)
    turtle.drop()

    turtle.turnLeft()
end

function plant()
    turtle.select(3)
    turtle.place()
    turtle.select(2)
    turtle.place()
    turtle.select(16)
    while turtle.compare()==false do
        turtle.select(2)
        turtle.place()
        turtle.select(16)
    end
end

function turn()
    turtle.turnLeft()
    turtle.turnLeft()
end

function crash()
    for i=1,10 do
        turtle.down()
    end
    turtle.select(15)
    turtle.digUp()
    turtle.up()
    turn()
    if turtle.compare()==true then
        back()
        getWood()
        run()
    else
        turtle.turnLeft()
    if turtle.compare()==true then
        back()
        getWood()
        run()
    else
        turtle.turnLeft()
    if turtle.compare()==true then
        back()
        getWood()
        run()
    else
        turtle.turnLeft()
    if turtle.compare()==true then
        back()
        getWood()
        run()
    else
        print"error"
        os.exit()
    end
    end
    end
    end
end



function back()
    turn()
    turtle.down()
end

function run()
    checkFuel()
    plant()
    getWood()
    drop()
    supply()
end

crash()
while true do
    run()
end