import sys
#sys.setrecursionlimit(10 ** 6)
INF = float('inf')
#10**20に変えるのもあり
MOD = 10**9 + 7
MOD2 = 998244353
def solve():
    def II(): return int(sys.stdin.readline())
    def LI(): return list(map(int, sys.stdin.readline().split()))
    def LC(): return list(input())
    def IC(): return [int(c) for c in input()]
    def MI(): return map(int, sys.stdin.readline().split())
    N,K = MI()
    A = LI()
    if(K<=N):
        print(A[K-1])
        exit()
    Tmp = 0
    for k in range(N):
        Tmp ^= A[k]
    A.append(Tmp)
    K-=1
    #print(A,K%(N+1))
    print(A[K%(N+1)])
    return
solve()