/* -*- coding: utf-8 -*-
 *
 * 1569.cc:  No.1569 Nixoracci's Number - yukicoder
 */

#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<cmath>
#include<iostream>
#include<string>
#include<vector>
#include<map>
#include<set>
#include<stack>
#include<list>
#include<queue>
#include<deque>
#include<algorithm>
#include<numeric>
#include<utility>
#include<complex>
#include<functional>
 
using namespace std;

/* constant */

const int MAX_N = 200;

/* typedef */

typedef long long ll;
typedef int mat[MAX_N][MAX_N];

/* global variables */

ll as[MAX_N];
mat ma, mb;

/* subroutines */

inline void initmat(const int n, mat a) { memset(a, 0, sizeof(mat)); }

inline void unitmat(const int n, mat a) {
  initmat(n, a);
  for (int i = 0; i < n; i++) a[i][i] = 1;
}

inline void copymat(const int n, const mat a, mat b) {
  memcpy(b, a, sizeof(mat));
}

inline void mulmat(const int n, const mat a, const mat b, mat c) {
  for (int i = 0; i < n; i++)
    for (int j = 0; j < n; j++) {
      c[i][j] = 0;
      for (int k = 0; k < n; k++)
        c[i][j] ^= a[i][k] * b[k][j];
    }
}

inline void powmat(const int n, const mat a, ll b, mat c) {
  mat s, t;
  copymat(n, a, s);
  unitmat(n, c);

  while (b > 0) {
    if (b & 1) {
      mulmat(n, c, s, t);
      copymat(n, t, c);
    }

    mulmat(n, s, s, t);
    copymat(n, t, s);
    b >>= 1;
  }
}

/* main */

int main() {
  int n;
  ll k;
  scanf("%d%lld", &n, &k);
  for (int i = 0; i < n; i++) scanf("%lld", as + i);

  initmat(n, ma);
  for (int i = 0; i + 1 < n; i++) ma[i][i + 1] = 1;
  for (int j = 0; j < n; j++) ma[n - 1][j] = 1;

  powmat(n, ma, k - 1, mb);

  ll sum = 0;
  for (int i = 0; i < n; i++) sum ^= mb[0][i] * as[i];

  printf("%lld\n", sum);
  return 0;
}