#include<bits/stdc++.h>
using namespace std;
#define fi first
#define se second
#define pb push_back
#define eb emplace_back
#define vi vector<int>
#define pi pair<int,int>
#define sz(v) (int)(v).size()
#define all(v) (v).begin(), (v).end()
#define compact(v) (v).erase(unique(all(v)), (v).end())
template<class T> using upq = priority_queue<T, vector<T>, greater<T>>;
template<class T> int lwrbound(const vector<T>& a, const T& b, const int s = 0){return int(lower_bound(s + all(a), b) - a.begin());}
template<class T> int uprbound(const vector<T>& a, const T& b, const int s = 0){return int(upper_bound(s + all(a), b) - a.begin());}
#define FOR(i, a, b) for(int i = (a); i <= (b); i++)
#define ROF(i, a, b) for(int i = (a); i >= (b); i--)
#define sumof(x) accumulate(all(x), 0ll)
#define dbg(x) "[" << #x " = " << (x) << "]"
#define el "\n"
using ll = long long;
using ld = long double;
template<class T> bool ckmx(T& a, const T b){return (a < b ? a = b, true : false);}
template<class T> bool ckmn(T& a, const T b){return (a > b ? a = b, true : false);}
const int lg = 29;
/*
brute:
+ fix a number x and bit B
+ get prefix sum in range [tL, tR]
*/
void Main()
{
int N; cin >> N;
vi a(N + 1), o, z, v;
FOR(i, 1, N){
cin >> a[i];
((a[i] & 1) ? o.eb(i) : z.eb(i));
}
v.insert(v.end(), all(z));
v.insert(v.end(), all(o));
int ans = 0;
FOR(b, 0, lg + 1){
vector<pi> range;
range.eb(pi((1ll << b), (1ll << b + 1) - 1));
range.eb(pi((1ll << b + 1) | (1ll << b), (1ll << b + 2) - 1));
auto f = [&](int x) -> int{
return (a[x] & ((1 << b + 1) - 1));
};
int cnt = 0;
FOR(_, 0, 1){
int L, R; L = R = sz(v) - 1;
FOR(i, 0, sz(v) - 1){
while(R >= i && f(v[R]) + f(v[i]) > range[_].se) --R;
while(L >= i && f(v[L]) + f(v[i]) >= range[_].fi) --L;
if(R >= i){
cnt ^= ((R - max(i - 1, L)) & 1);
}
}
}
ans = ans | (cnt << b);
o.clear(), z.clear();
for(int i : v){
(((a[i] >> (b + 1)) & 1) ? o.eb(i) : z.eb(i));
}
v.clear();
v.insert(v.end(), all(z));
v.insert(v.end(), all(o));
}
cout << ans << el;
}
int32_t main()
{
ios_base::sync_with_stdio(0);
cin.tie(0); cout.tie(0);
#define name "InvMOD"
if(fopen(name".INP", "r")){
freopen(name".INP", "r", stdin);
freopen(name".OUT", "w", stdout);
}
int t = 1; while(t--) Main();
return 0;
}
