#include <bits/stdc++.h>
using namespace std;
const int MAX = 1 << 25;
int tr[MAX];
int main() {
	int n;
	scanf("%d", &n);
	vector<int> pref{0};
	for(int i = 0; i < n; ++i) {
		int x;
		scanf("%d", &x);
		pref.push_back(pref.back() + x);
	}
	int answer = 0;
	for(int which = 0; (1 << which) <= pref.back(); ++which) {
		const int half = 1 << which;
		const int mod = 2 * half;
		assert(2 * mod <= MAX);
		for(int i = 0; i < 2 * mod; ++i)
			tr[i] = 0;
		for(int x : pref) {
			x %= mod;
			bool flag = false;
			int low = (x + 1) % mod, high = (x + half) % mod;
			if(low > high) {
				flag = true;
				pair<int,int> tmp = {high + 1, low - 1};
				low = tmp.first, high = tmp.second;
			}
			assert(0 <= low && low <= high && high < mod);
			low += mod, high += mod;
			int cnt = tr[low];
			if(low != high) cnt += tr[high];
			while(low < high - 1) {
				if(low % 2 == 0) cnt += tr[low+1];
				if(high % 2) cnt += tr[high-1];
				low /= 2, high /= 2;
			}
			if(flag) cnt = tr[1] - cnt;
			if(cnt % 2 != 0)
				answer ^= half;
			for(int i = mod + x; i >= 1; i /= 2)
				++tr[i];
		}
	}
	printf("%d\n", answer);
}