# -*- coding: utf-8 -*-
def ch(password):
    N = len(password)
    sep = list(password)
    for i in range(0, N):
        if sep[i].islower():
            sep[i] = sep[i].upper()
        elif sep[i].isupper():
            sep[i] = sep[i].lower()
    return "".join(sep)


password = raw_input()
print ch(password)