#include <bits/stdc++.h>
#define IOS\
	ios::sync_with_stdio(false);\
	cin.tie(0), cout.tie(0);

using namespace std;

const int N = 1e6 + 3;

int a[N], n, h1, h2;
char ch[10];

signed main() {
	srand(time(0));
	mt19937 mt(114514);
	IOS;
	for (int i = 1; i < N; i++) {
		a[i] = mt();
	}
//	cout << a[483440] << '\n';
	cin >> ch;
	if (ch[0] == 'r') {
		cin >> h1 >> h2;
	}
	cin >> n;
	for (int i = 1, x; i <= n; i++) {
		cin >> x;
		h1 ^= x;
		h2 ^= a[x];
		if (!h1 && !h2) {
			cout << "0\n";
		}
		else if (a[h1] == h2) {
			cout << h1 << '\n';
		}
		else cout << "-1\n";
	}
	if (ch[0] == 's') cout << h1 << " " << h2 << '\n';
	return 0;
}