10. Let $S_{n}=1+\frac{1}{1+\frac{1}{3}}+\frac{1}{1+\frac{1}{3}+\frac{1}{6}}+\cdots+\frac{1}{1+\frac{1}{3}+\frac{1}{6}+\cdots+\frac{1}{k_{n}}}$, where $k_{n}=$ $\frac{n(n+1)}{2}\left(n \in \mathbf{N}_{+}\right)$, and let $T_{0}$ be the largest integer $T$ that satisfies the inequality $S_{2006}>T$. Among the numbers $2006, 2008, 1006, 1005$, the one closest to $T_{0}$ is $\qquad$