Solution (source code)

= Solution

For each <integer> $m$, take $\gamma_m(t)=e^{2\pi imt}$. It is a continuous closed curve avoiding zero and has the continuous argument $2\pi mt$. Consequently
$$
\boxed{w(\gamma_m)=m,\qquad m\in\mathbb Z.}
$$
Positive and negative <integers> correspond to opposite senses of traversal, and the constant curve gives zero.