function dig()
    repeat turtle.dig() until not turtle.detect()
end

function forward()
    repeat until turtle.forward()
end

function up()
    repeat until turtle.up()
end

function down()
    repeat until turtle.down()
end




function slice()
    dig()
    forward()
    turtle.turnLeft()
    dig()
    turtle.digUp()
    up()
    dig()
    turtle.digUp()
    up()
    dig()
    turtle.turnRight()
    turtle.turnRight()
    dig()
    down()
    dig()
    down()
    dig()
    turtle.turnLeft()
end

function goBack(dist)
    for i=1,dist do
        turtle.forward()
    end
end

function refuel()
    for i=1,16 do
        turtle.select(i)
        turtle.refuel(64)
    end
end


write("Distance:")
local a=0
a=read()

for i=1,a do
    slice()
    while turtle.getFuelLevel() < a*5 do
        print("waiting for fuel...")
        refuel()
    end
end
    turtle.turnLeft()
    turtle.turnLeft()
    goBack(a)