"""
a[i]=a[i-1]^a[i-2]^...^a[i-n]
a[i+1]=a[i]^a[i-1]^...^a[i-n+1]
a[i+1]=a[i]^(a[i]^a[i-n])
a[i+1]=a[i-n]
a[i]=a[i-n-1]
mod (n+1)で同じなら同じ
"""
def main2(n,k,a):
  if k<=n:return a[k-1]
  tmp=0
  for i in range(n):
    tmp^=a[-1-i]
  a.append(tmp)
  k-=1
  return a[k%(n+1)]

if __name__=='__main__':
  n,k=map(int,input().split())
  a=list(map(int,input().split()))
  print(main2(n,k,a))