// Source: https://usaco.guide/general/io #include <bits/stdc++.h> using namespace std; int n, a[1000005]; int main() { cin >> n; for (int i = 1; i <= n; i++) cin >> a[i]; int ans = 0; for (int i = 0; i < 30; i++) { vector <int> v; for (int j = 1; j <= n; j++) { v.push_back(a[j] % (1ll<<(i + 1))); } sort(v.begin(), v.end()); long long tmp = 0; for (int j = 1; j <= n; j++) { int x = a[j] % (1ll<<(i + 1)); int l = (1ll<<i) - x, r = (1ll<<(i + 1)) - 1 - x; if(l >= 0) tmp += upper_bound(v.begin(), v.end(), r) - lower_bound(v.begin(), v.end(), l); else { tmp += v.end() - lower_bound(v.begin(), v.end(), l + (1ll<<(i + 1))); tmp += upper_bound(v.begin(), v.end(), r) - v.begin(); } //cout << tmp << ' '; } //cout << tmp << '\n'; //tmp /= 2; if (tmp & 1) ans ^= (1ll<<i); } cout << ans; }