def swap_case(s):
    res = ""
    for c in s:
        if c.isalpha and c.islower():
            res += c.upper()
        elif c.isalpha and c.upper():
            res += c.lower()
        else:
            res += c
    return res

def swap_case(s):
    return s.swapcase()

if __name__ == '__main__':
    s = input()
    result = swap_case(s)
    print(result)

def swap_case(s):
    new_s = ''
    for i in s:
        if i.upper() == i:
            new_s += i.lower()
        else:
            new_s += i.upper()
    return new_s

if __name__ == '__main__':
    s = input()
    result = swap_case(s)
    print(result)