#include <bits/stdc++.h>

int main() {
  using namespace std;
  cin.tie(nullptr)->sync_with_stdio(false);
  int n;
  cin >> n;
  int64_t k;
  cin >> k;
  --k;
  vector<int64_t> a(n);
  for (auto&& e : a) cin >> e;
  a.push_back(accumulate(begin(a), end(a), int64_t(0), bit_xor{}));
  ++n;
  cout << a[k % n] << '\n';
}