Invert Case

Given a string, your task is to invert the case of every alphabetical character. Specifically, each uppercase letter should be converted to lowercase, and each lowercase letter to uppercase. Non-alphabet characters should remain unchanged.

For example, if the input is Hello World!, the output should be hELLO wORLD!.

inputFormat

A single line containing the input string.

outputFormat

Print the string after converting each uppercase letter to lowercase and each lowercase letter to uppercase. Non-alphabet characters should remain unchanged.## sample

Hello World!

hELLO wORLD!