## Task 1 - 050831

Determine the number of all numbers between 10000 and 99999 that, like 35453, read the same sequence of digits forwards as backwards.
The sought number is equal to the number of all three-digit numbers, since from each three-digit number exactly one such number results if the first two digits of the number are written in reverse order behind the number, and conversely, each such five-digit number is obtained from a three-digit number.

Since there are 900 three-digit numbers, the sought number is 900.