Problem 1: Alternating Sums

Background:

What? Another alternating sums problem? Must every contest begin with alternating sums? Of course it must!

Did you know that a positive integer is evenly divisible by 11 if and only if the alternating sum of it's digits is evenly divisible by 11? Well, it's a fact, just look around: 121 -> 0, 108152 -> 11, 9090909091 -> 44, 1909090909 -> -44, etc. but 98 -> 1, 7889 -> -2, 123456789 -> -5, etc.

Input:

The input will consist zero or more positive integers separated by white space. The integers will have at most 256 digits.

Output:

Echo the numbers to output, one per line. Follow each number with "is divisible by 11" or "is not divisible by 11" as appropriate. For an empty input (containing no numbers), no output should be written.

Sample Input:

11 909090909080909090909
1331
123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890

Sample Output:

11 is divisible by 11.
909090909080909090909 is not divisible by 11.
1331 is divisible by 11.
123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890 is not divisible by 11.