10. Let $M=\{1,2,3, \cdots, 1995\}, A \subseteq M$, and when $x \in A$, $19 x \notin A$. Find the maximum value of $|A|$.

 untranslated portion:
设 $M=\{1,2,3, \cdots, 1995\}, A \subseteq M$, 且当 $x \in A$ 时, $19 x \notin A$, 求 $|A|$的最大值.

 translated portion:
Let $M=\{1,2,3, \cdots, 1995\}, A \subseteq M$, and when $x \in A$, $19 x \notin A$. Find the maximum value of $|A|$.
10. From the problem, we know that at least one of the numbers $k$ and $19k$ (where $k=6,7, \cdots, 105$) does not belong to $A$, so $|A| \leqslant 1995-(105-6+1)=1895$. Let $B=\{1,2,3,4,5\}$, $C=\{106,107, \cdots, 1995\}$, and $A=B \cup C$, then $|A|=1895$, and there is no number in $A$ that is 19 times another number in $A$.

If $k \in A$, when $k \in B$, $19 \leqslant 19k \leqslant 105$, $19k \notin A$; when $k \in C$, $19k \geqslant 106 \times 19>1995$, $19k \notin A$. Therefore, the maximum value of $|A|$ is 1895.