CC Tweaked, Im trying to make a quarry program but im gettting a error about Comparing a number with a string, but both values are numbers

Solution for CC Tweaked, Im trying to make a quarry program but im gettting a error about Comparing a number with a string, but both values are numbers
is Given Below:

The error I get:

query.lua:25: attempt to compare number with string

The rest of my code – I’m not sure why its not working, because I made sure that both values were in fact numbers, and the error still keeps happening, I have tried looking it up, and I cant find a solution, any help would be greatly appreciated.

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