def main():
    s = input()
    list_s = list(str(s))

    for i in range(len(list_s)):
        if list_s[i].islower():
            list_s[i] = list_s[i].upper()
        else:
            list_s[i] = list_s[i].lower()

    print("".join(list_s))


if __name__ == "__main__":
    main()