import java.io.*; import java.util.*; import java.util.function.*; import java.util.stream.*; public class Main { public static void main(String[] args) throws Exception { Scanner sc = new Scanner(); int n = sc.nextInt(); long k = sc.nextLong() - 1; long[] values = new long[n + 1]; long current = 0; for (int i = 0; i < n; i++) { values[i] = sc.nextLong(); current ^= values[i]; } values[n] = current; System.out.println(values[(int)(k % (n + 1))]); } } class Scanner { BufferedReader br; StringTokenizer st = new StringTokenizer(""); StringBuilder sb = new StringBuilder(); public Scanner() { try { br = new BufferedReader(new InputStreamReader(System.in)); } catch (Exception e) { } } public int nextInt() { return Integer.parseInt(next()); } public long nextLong() { return Long.parseLong(next()); } public double nextDouble() { return Double.parseDouble(next()); } public String next() { try { while (!st.hasMoreTokens()) { st = new StringTokenizer(br.readLine()); } } catch (Exception e) { e.printStackTrace(); } finally { return st.nextToken(); } } }