#include <iostream> #include <algorithm> using namespace std; const int N = 1<<20; int ord[N], ord2[N], a[N], b[N], cnt[N], c[N], l1[N], l2[N], r1[N]; void solve(int n, int k){ int z = 0; for (int i=1;i<=n;i++){ if ((1<<k) & a[i]) b[i] += (1<<k); else z++; swap(ord[i], ord2[i]); } for (int i=1, O = 0, Z = 0;i<=n;i++){ if (b[ord2[i]] & (1<<k)) O++, ord[z + O] = ord2[i]; else Z++, ord[Z] = ord2[i]; } for (int i=1;i<=n;i++) c[i] = b[ord[i]]; for (int i=1, r = n + 1;i<=n;i++){ while (r - 1 >= i and c[i] + c[r - 1] >= (1<<k)) r--; l1[i] = max(i, r); } for (int i=1, r = n + 1;i<=n;i++){ while (r - 1 >= i and c[i] + c[r - 1] >= (2<<k)) r--; r1[i] = max(i, r); } for (int i=1, r = n + 1;i<=n;i++){ while (r - 1 >= i and c[i] + c[r - 1] >= (1<<k) + (2<<k)) r--; l2[i] = max(i, r); } for (int i=1;i<=n;i++){ cnt[k] ^= (n + 1 - l2[i]) & 1; cnt[k] ^= (r1[i] - l1[i]) & 1; } } int main(){ ios_base::sync_with_stdio(false); cin.tie(NULL); int n, Ans = 0, ln = 0; cin>>n; for (int i=1;i<=n;i++) cin>>a[i], ord[i] = i, ln = max(ln, 31 - __builtin_clz(a[i])); // cout<<ln<<'\n'; for (int i=0;i<=ln+1;i++) solve(n, i); for (int i=0;i<=ln+1;i++) Ans |= cnt[i]<<i; cout<<Ans<<'\n'; }