6. Da Guang read a book, the number of pages read on the first and second days are two two-digit numbers composed of the digits $1$, $9$, $8$, and $3$, and the number of pages read on the second day is exactly equal to the sum of these four digits more than the first day. How many pages did he read on the first and second days?
6. On the first day, read 18 pages, on the second day, read 39 pages,
$$
39-18=1+9+8+3 \text {. }
$$