"""

https://yukicoder.me/problems/no/1569

A[N] は全部のXOR
A[N+1] は A[0]
N+1 個周期

"""

from sys import stdin

N,K = map(int,stdin.readline().split())

A = list(map(int,stdin.readline().split()))

K -= 1

now = 0
for i in A:
    now ^= i
A.append(now)

print (A[K % (N+1)])