#!/usr/bin/env python3
# -*- coding: utf-8-*-
if __name__ == '__main__':
    s = input()
    a = []
    for i in s:
        if ord(i) < 97:
            a.append(chr(ord(i)+32))
        else:
            a.append(chr(ord(i)-32))
    print("".join(a))