// 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; int mx = 0; for (int j = 1; j <= n; j++) { int x = a[j] % (1ll<<(i + 1)); mx = max(mx, a[j]); v.push_back(mx); } if (i && mx < (1ll<<(i - 1))) break; sort(v.begin(), v.end()); long long tmp = 0, tmp2 = 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); if (l <= x && x <= r) tmp--, tmp2++; } else { tmp += v.end() - lower_bound(v.begin(), v.end(), l + (1ll<<(i + 1))); tmp += upper_bound(v.begin(), v.end(), r) - v.begin(); if (x <= r || x >= l + (1ll<<(i + 1))) tmp--, tmp2++; } //cout << tmp << ' '; } tmp /= 2; tmp += tmp2; //cout << tmp << '\n'; //tmp /= 2; if (tmp & 1) ans ^= (1ll<<i); } cout << ans; }