25. Express 2006 as the sum of $n(n \geqslant 3)$ consecutive natural numbers. Please write two expressions.
$$
\begin{array}{l}
25.500+501+502+503,110+111+112+\cdots+ \\
126,5+6+7+\cdots+63 .
\end{array}
$$
(Provided by Hong Wangbao)