Cosets and Lagrange's Theorem · Easy problem

In $\mathbb Z_{18}$, let $H = \langle 6\rangle = \{0,6,12\}$. The element $34$ (reduced mod $18$) lies in some left coset of $H$. What is the smallest nonnegative representative (an element of $\{0,1,\dots,17\}$) of that coset?