Odd Screams

Limits 1s, 512 MB

You will be given a string with one or more a’s. You have to write a regular expression that matches the string only if the number of a’s in the string is odd.

Input

The input will contain a string with one or more a’s. The string will have at most 25 characters.

Output

Output the string only if it has an odd number of a’s.

Samples

InputOutput
aaa
aaa
InputOutput
aa