|VK Cup 2012 Wild-card Round 1|
You are given a string consisting of alphabet letters. Convert it to alternating case: the letters on odd positions should be in uppercase, and the letters on even positions should be lowercase. The letters are numbered staring from 1.
The only line of input contains a string between 1 and 100 characters long. Each character of the string is either an uppercase ('A'-'Z') or a lowercase ('a'-'z') letter.
Output the resulting string.