def main():
    N,K = map(int,input().split())
    A = list(map(int,input().split()))
    v = 0
    for i in range(N):
        v ^= A[i]
    A.append(v)
    #print(A)
    if K%(N+1) == 0:
        ans = A[-1]
    else:
        ans = A[(K-1)%(N+1)]
    print(ans)


if __name__ == '__main__':
    main()