10. The use of passwords is extremely important in modern society. There is a plaintext (real text) in which the letters correspond to the 26 natural numbers $1,2, \cdots, 26$ according to the computer keyboard order (from left to right, from top to bottom) (see Table 1).
Table 1
\begin{tabular}{|c|c|c|c|c|c|c|c|c|c|c|c|c|}
\hline$Q$ & $W$ & $E$ & $R$ & $T$ & $Y$ & $U$ & $I$ & 0 & $P$ & $A$ & $S$ & $D$ \\
\hline 1 & 2 & 3 & 4 & 5 & 6 & 7 & 8 & 9 & 10 & 11 & 12 & 13 \\
\hline \hline$F$ & $G$ & $H$ & $J$ & $K$ & $L$ & $Z$ & $X$ & $C$ & $V$ & $B$ & $N$ & $M$ \\
\hline 14 & 15 & 16 & 17 & 18 & 19 & 20 & 21 & 22 & 23 & 24 & 25 & 26 \\
\hline
\end{tabular}

Let the natural number corresponding to any letter in the plaintext be $x$, and the natural number corresponding to the ciphertext letter after translation be $x^{\prime}$. For example, one decoding method is implemented according to the following transformation:
$x \rightarrow x^{\prime}$, where $x^{\prime}$ is the remainder of $(3 x+2)$ divided by 26 plus 1 $(1 \leqslant x \leqslant 26)$.
For $x=1$, $x^{\prime}=6$, meaning the plaintext $Q$ is translated to the ciphertext $Y$; for $x=10$, $x^{\prime}=7$, meaning the plaintext $P$ is translated to the ciphertext $U$.
There is a certain transformation that changes the natural number $x$ corresponding to the plaintext letter to the natural number $x^{\prime}$ corresponding to the ciphertext letter:
$x \rightarrow x^{\prime}, x^{\prime}$ is the remainder of $(3 x+b)$ divided by 26 plus 1 $(1 \leqslant x \leqslant 26,1 \leqslant b \leqslant 26)$.
It is known that using this transformation, the plaintext $H$ is translated to the ciphertext $T$. Then the plaintext DAY is translated to the ciphertext as
10. $\mathrm{CHQ}$