/**
* In the name of Allah
* We are nothing and you're everything
* author: najmuddin
**/
#include <bits/stdc++.h>
#pragma GCC optimize("O3")
#pragma GCC target("avx2")
#pragma GCC optimize("Ofast")
#pragma GCC optimize("unroll-loops")
#pragma GCC optimize("no-stack-protector")
#pragma GCC optimize("fast-math")
#pragma GCC optimize("trapv")
#pragma GCC optimize("inline")
using namespace std;
#define all(x) begin(x), end(x)
#define sz(x) (int)(x).size()
typedef long long ll;
#define int ll
const char nl = '\n';
const int N = 2e5+5;
const int inf = 1e9;
const int mod = 998244353;
void solve() {
int n; cin >> n;
vector<int> a(n);
for (auto &i: a)cin >> i;
int total = 0;
for (int i = 0; i < n; ++i) {
int x = a[i];
int xorsum = 0;
for (int j = i; j < n; ++j)
xorsum ^= (a[j]+x);
total ^= xorsum;
}
cout << total;
}
int32_t main() {
ios::sync_with_stdio(0);
cin.tie(0);
int t = 1;
//cin >> t;
while (t--) {
solve();
}
return 0;
}
