N, K = map(int, input().split())

A = list(map(int, input().split()))

for _ in range(201):
  next = 0
  count = 0
  for a in reversed(A):
    count += 1
    next ^= a
    if count == N:
      break
  A.append(next)

idx = K%(N+1)
if K <= N+1:
  print(A[:N+1][K-1])
else:
  print(A[:N+1][idx-1])