#include <bits/stdc++.h> #define GOOD_LUCK ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0); #define int long long #define endl "\n" #define ff first #define ss second #define pb push_back #define all(v) v.begin(), v.end() using namespace std; constexpr int MAX = 2e+5 + 1, INF = 2e+9, MOD = 1e+9 + 7, K = 28; void mysort(vector <int> &v) { int n = v.size(); vector <int> o = v; int ma=*max_element(all(v)); int b = sqrt(ma * 2) + 10; vector <int> id; for (int i = 0; i < n; i++) id.pb(i); for (int i = 0; i < 2; i++) { vector <vector <int>> c(b); for (int &j : id) { int x = v[j] % b; v[j] /= b; c[x].pb(j); } id.clear(); for (int j = 0; j < b; j++) { for (int &z : c[j]) id.pb(z); } } for (int i=0; i < n; i++) v[i] = o[id[i]]; } int get(vector <int> &v, int x) { int res = 0; int l = 0, r = v.size()-1; while (l < r) { if (v[l] + v[r] <= x) { res += r - l; l++; } else r--; } for (int &i : v) { if (2 * i <= x) res++; } return res; } void _() { int n; cin >> n; vector <int> v(n); for (int &i : v) cin >> i; int res=0; for (int i = K; i >= 0; i--) { vector <int> x = v; int m = (1LL << (i + 1)); for (int &j : x) j %= m; mysort(x); int c=0; int mn = (1LL << i); int mx = (1LL << (i + 1)) - 1; if (mn <= mx) c += get(x, mx) - get(x, mn-1); mn = (1LL << i) * 3; mx = (1LL << (i + 2)) - 1; if (mn <= mx) c += get(x, mx) - get(x, mn-1); res += (1LL << i) * (c % 2); } cout << res; } signed main() { GOOD_LUCK int tests=1; // cin >> tests; for (int i=1; i <= tests; i++) { _(); cout << endl; } return 0; } /* 0011 0110 0110 1001 001 011 110 110 100 -> min 111 -> max */