CC 调整，我正在尝试制作一个采石场程序，但我在将数字与字符串进行比较时遇到错误，但两个值都是数字

Question

有问题的错误代码：quary.lua:25: attempt to compare number with string

我的其余代码 我不确定为什么它不起作用，因为我确定这两个值实际上都是数字，并且错误仍然不断发生，我已经尝试查找它，但我找不到解决方案，任何帮助都将不胜感激。

print("Enter L,W,H values")
x = read()
y = read()
z = read()

length = 5
width = 5
height = 5

length = x
width = y
height = z

volume = length * width * height
print(volume.." blocks to mine")
turtle.refuel()
turtleFuel = turtle.getFuelLevel()
fuelNeeded = turtleFuel - volume
if fuelNeeded >= 0 then
    print("Enough Fuel Detected")
else
    print("not Enough fuel, error,"..fuelNeeded..", fuel required "..volume)
end
length1 = length
while length1 > 0 do
    turtle.forward()
    length1 = length1 - 1
end