# ACM MidAtlantic-2010

# Palindometer

While driving the other day, John looked down at his odometer, and it read **100000**. John was pretty excited about that. But, just one mile further, the odometer read **100001**, and John was REALLY excited! You see, John loves palindromes - things that read the same way forwards and backwards. So, given any odometer reading, what is the least number of miles John must drive before the odometer reading is a palindrome? For John, every odometer digit counts. If the odometer reading was **000121**, he wouldn't consider that a palindrome.

#### Input

There will be several test cases, each consisting of an odometer reading on its own line. Each odometer reading will be from **2** to **9** digits long. The odometer in question has the number of digits given in the input - so, if the input is **00456**, the odometer has **5** digits. There will be no spaces in the input, and no blank lines between input sets.

The data will end with a line with a single **0**.

#### Output

For each test case, output the minimum number of miles John must drive before the odometer reading is a palindrome. This may be **0** if the number is already a palindrome. Output each integer on its own line.

100000 100001 000121 00456 0

1 0 979 44