#include <bits/stdc++.h>
#define rep(i, n) for (int i = 0; i < (n); ++i)

using std::cin;
using std::cout;
using std::vector;
using ll = long long;

int main() {
	int n;
	ll k;
	cin >> n >> k;
	
	vector<ll> a(n + 1);
	rep(i, n) cin >> a[i];
	rep(i, n) a[n] ^= a[i];
	
	ll ans = a[(k - 1) % (n + 1)];
	cout << ans << '\n';
	
	return 0;
}