Language: C++

}
signed main() {
	int n; cin >> n;
	vel a(n);
	int sum = 0;
	rep(i, n) { cin >> a[i]; sum ^= a[i]; }
	if (sum != 0) {
		int ne = 0;
		int ko = 0;
		int go = sum;
		rep(i, n) {
			ne ^= a[i];
			if (ne == go) { ko++; go ^= sum; }
		}
		int ans = 1;
		if (ko != 1) {
			rep(i, ko - 2) {
				ans *= 2;
				ref(ans);
			}
		}
		cout << ans << endl;
	}
	else {
		int ne = 0;
		int ko = 0;
		vector<vel> kug(1); int big = 0;
		vel list(0);
		rep(i, n) {
			ne ^= a[i];
			if (ne != 0) {
				list.push_back(ne);
				kug[big].push_back(ne);
			}
			if (ne == sum) { ko++; kug.push_back(vel(0)); big++; }
		}
		int ans = 1;
		rep(i, ko-1) {
			ans *= 2;
			ref(ans);
		}
		vel ql=uni(list);
		int sz = ql.size();
		vel back(sz, -1);  vel dp0(sz, 1); vel dp1(sz, 0);
		rep(i, kug.size()) {
			vel unk = uni(kug[i]);
			int sz2 = unk.size();
			vel mul2(sz2, 0);
			vel exa(sz2, 0);
			vel wri(sz2, 0);
			rep(j, kug[i].size()) {
				int pot1 = lower_bound(ql.begin(), ql.end(), kug[i][j]) - ql.begin();
				int pot2 = lower_bound(unk.begin(), unk.end(), kug[i][j]) - unk.begin();
				mul2[pot2]++;
			}
			rep(j, sz2) {
				int pot1 = lower_bound(ql.begin(), ql.end(), unk[j]) - ql .begin();
				if (back[pot1] == -1) { back[pot1] = i; dp1[pot1] = mul2[j]; }
				else if (back[pot1] != i) {
					int ne0 = dp1[pot1] * (i - back[pot1]); ref(ne0);
					ne0 *= mul2[j]; ref(ne0); ne0 += dp0[pot1]; ref(ne0);
					int ne1 = (dp1[pot1])*(i - back[pot1]); ref(ne0);
					ne1 = ne1 * mul2[j] + dp1[pot1] + dp0[pot1]; ref(ne1);
					dp0[pot1] = ne0; dp1[pot1] = ne1; ref(dp0[pot1]); ref(dp1[pot1]);
					back[pot1] = i;
				}
			}
		}
		rep(j, sz) {
			int qans = dp1[j];
			ans += qans; ref(ans);
		}
		cout << ans << endl;
	}
	return 0;
}

Compiler output:
a.cc:1:1: error: expected declaration before '}' token
    1 | }
      | ^
a.cc: In function 'int main()':
a.cc:3:16: error: 'cin' was not declared in this scope
    3 |         int n; cin >> n;
      |                ^~~
a.cc:4:9: error: 'vel' was not declared in this scope
    4 |         vel a(n);
      |         ^~~
a.cc:6:13: error: 'i' was not declared in this scope
    6 |         rep(i, n) { cin >> a[i]; sum ^= a[i]; }
      |             ^
a.cc:6:9: error: 'rep' was not declared in this scope
    6 |         rep(i, n) { cin >> a[i]; sum ^= a[i]; }
      |         ^~~
a.cc:22:17: error: 'cout' was not declared in this scope
   22 |                 cout << ans << endl;
      |                 ^~~~
a.cc:22:32: error: 'endl' was not declared in this scope
   22 |                 cout << ans << endl;
      |                                ^~~~
a.cc:27:17: error: 'vector' was not declared in this scope
   27 |                 vector<vel> kug(1); int big = 0;
      |                 ^~~~~~
a.cc:27:29: error: 'kug' was not declared in this scope
   27 |                 vector<vel> kug(1); int big = 0;
      |                             ^~~
a.cc:28:20: error: expected ';' before 'list'
   28 |                 vel list(0);
      |                    ^~~~~
      |                    ;
a.cc:42:20: error: expected ';' before 'ql'
   42 |                 vel ql=uni(list);
      |                    ^~~
      |                    ;
a.cc:43:26: error: 'ql' was not declared in this scope
   43 |                 int sz = ql.size();
      |                          ^~
a.cc:44:20: error: expected ';' before 'back'
   44 |                 vel back(sz, -1);  vel dp0(sz, 1); vel dp1(sz, 0);
      |                    ^~~~~
      |                    ;
a.cc:44:39: error: expected ';' before 'dp0'
   44 |                 vel back(sz, -1);  vel dp0(sz, 1); vel dp1(sz, 0);
      |                                       ^~~~
      |                                       ;
a.cc:44:55: error: expected ';' before 'dp1'
   44 |                 vel back(sz, -1);  vel dp0(sz, 1); vel dp1(sz, 0);
      |                                                       ^~~~
      |                                                       ;
a.cc:69:21: error: 'j' was not declared in this scope
   69 |                 rep(j, sz) {
      |                     ^
a.cc:73:17: error: 'cout' was not declared in this scope
   73 |                 cout << ans << endl;
      |                 ^~~~
a.cc:73:32: error: 'endl' was not declared in this scope
   73 |                 cout << ans << endl;
      |                                ^~~~