local firstItem,lastItem = 2,16

function lootAll()
    for i=firstItem,lastItem do
        turtle.select(i)
        turtle.suck()
    end
end

function placeAll()
    for i=firstItem,lastItem do
        turtle.select(i)
        turtle.drop()
    end
end

function turnAround()
    turtle.turnLeft()
    turtle.turnLeft()
end

function walk(x)
    for i=1,x do
        turtle.forward()
    end
end

function walkUntilObstructed()
    local walking = true
    local walked = 0
    while walking do
        if turtle.detect() then
            walking = false
        else
            walked = walked + 1
            turtle.forward()
        end
    end
    return walked
end
local initialFuel = turtle.getFuelLevel()
lootAll()
turnAround()
walkUntilObstructed()
placeAll()
turnAround()
walkUntilObstructed()
local finalFuel = turtle.getFuelLevel()
print("Used Fuel:", initialFuel - finalFuel)