def main():
    F0, F1, N = map(int, input().split())
    F0_xor_F1 = get_xor(F0, F1)

    if N % 3 == 0:
        print(F0)
    elif N % 3 == 1:
        print(F1)
    else:
        print(F0_xor_F1)

def get_xor(a, b):
    ans = ""
    a_bin = format(a, 'b')
    b_bin = format(b, 'b')
    if len(a_bin) > len(b_bin):
        b_bin = ("0" * (len(a_bin) - len(b_bin))) + b_bin
    elif len(a_bin) < len(b_bin):
        a_bin = ("0" * (len(b_bin) - len(a_bin))) + a_bin
    print(a_bin, b_bin)
    for a, b in zip(list(a_bin), list(b_bin)):
        if a == b:
            ans += "0"
        else:
            ans += "1"
    print(ans)
    return int(ans, 2)

if __name__ == '__main__':
        main()