#!/usr/bin/env python3
import sys

def main():
    N, K = map(int,input().split())
    A = list(map(int,input().split()))
    c = 0
    for aa in A:
        c ^= aa
    A.append(c)
    print(A[(K - 1) % len(A)])

if __name__ == '__main__':
    main()