#include <iostream>
#include <vector>
#include <string>
#include <algorithm>
using namespace std;
using ll = long long;
using ull = unsigned long long;
#define rep(i,n) for(int i=0; i<(n); i++)

int N;
ull K;
vector<ull> A;

int main(){
  cin >> N >> K;
  A.resize(N);
  rep(i,N) cin >> A[i];
  A.push_back(0);
  rep(i,N) A[N] ^= A[i];
  ull ans = A[(K-1)%(N+1)];
  cout << ans << endl;
  return 0;
}

struct ios_do_not_sync{
  ios_do_not_sync(){
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
  }
} ios_do_not_sync_inst;