In the first test case, the heights of the mountains could go from $(5, 3, 6, 2)$ to $(3, 2, 4, 2)$ in just two years:
\begin{itemize}
\item Suppose that in the first year, $x = 4$. After this year, the heights of the mountains are $(4, 3, 5, 2)$.
\item Suppose that in the second year, $x = 3$. After this year, the heights of the mountains are $(3, 2, 4, 2)$.
\end{itemize}