请教一道题的解法。

ub_serain

If w, x, y, and z are on-negative integers, each less than 3, and w(3^3)+x(3^2)+y(3)+z=34, then w+z=?
A.0  B.1  C.2  D.3  E.4
The answer is C. Can any one tell me how to get this answer?

Thank you.

LittleLilyLiAng

我也认为答案是1。

noapple

first, what's mean on-negative?

if w=0, x=3, y=2, z=1  9*3+3*2+1=34
then w+z=1

why the answer is C ?