#include <bits/stdc++.h>
using namespace std;
using ll = long long;
#define rep(i, s, e) for (int i = (int)s; i < (int)e; ++i)
#define all(a) (a).begin(), (a).end()

int main() {
    cin.tie(nullptr);
    
    ll N, K;
    cin >> N >> K;
    vector<ll> A(N);
    rep(i, 0, N) cin >> A[i];
    
    A.push_back(0);
    rep(i, 0, N) A[N] ^= A[i];
    
    K--;
    K %= N + 1;
    
    cout << A[K] << '\n';
}