#include <stdio.h>

int main()
{
	int i, N;
	long long K, A[201];
	scanf("%d %lld", &N, &K);
	for (i = 0, A[N] = 0; i < N; i++) {
		scanf("%lld", &(A[i]));
		A[N] ^= A[i];
	}
	printf("%lld\n", A[(K-1)%(N+1)]);
	fflush(stdout);
	return 0;
}