#include <vector>
#include <iostream>
#include <algorithm>
using namespace std;
int solve(int N, vector<int> A) {
	vector<int> B(2 * N - 1);
	for (int i = 0; i <= 2 * N - 2; ++i) {
		vector<int> seq = { A[i], A[i + 1], A[i + 2] };
		if (seq == vector<int>({ 0, 1, 2 }) || seq == vector<int>({ 1, 2, 0 }) || seq == vector<int>({ 2, 0, 1 })) {
			B[i] = 1;
		}
		else if (seq == vector<int>({ 0, 2, 1 }) || seq == vector<int>({ 1, 0, 2 }) || seq == vector<int>({ 2, 1, 0 })) {
			B[i] = 2;
		}
		else {
			B[i] = 0;
		}
	}
	if (N == 1) {
		return B[0];
	}
	vector<int> s0, s1;
	for (int i = 0; i <= 2 * N - 2; ++i) {
		if (i % 2 == 1) {
			s0.push_back(0);
			s1.push_back(0);
		}
		else {
			s0.push_back(i % 4 == 0 ? 1 : 2);
			s1.push_back(i % 4 == 0 ? 2 : 1);
		}
	}
	if (B == (N % 2 == 0 ? s1 : s0)) {
		return 1;
	}
	else if (B == (N % 2 == 0 ? s0 : s1)) {
		return 2;
	}
	return 0;
}
int solve_easy(int N, vector<int> A) {
	for (int len = N; len >= 1; --len) {
		vector<int> B(2 * len - 1);
		for (int i = 0; i <= 2 * len - 2; ++i) {
			vector<int> seq = { A[i], A[i + 1], A[i + 2] };
			if (seq == vector<int>({ 0, 1, 2 }) || seq == vector<int>({ 1, 2, 0 }) || seq == vector<int>({ 2, 0, 1 })) {
				B[i] = 1;
			}
			else if (seq == vector<int>({ 0, 2, 1 }) || seq == vector<int>({ 1, 0, 2 }) || seq == vector<int>({ 2, 1, 0 })) {
				B[i] = 2;
			}
			else {
				B[i] = 0;
			}
		}
		A = B;
	}
	return A[0];
}
void random_check() {
	for (int N = 1; N <= 8; ++N) {
		int mul = 1;
		for (int i = 0; i < 2 * N + 1; ++i) {
			mul *= 3;
		}
		for (int i = 0; i < mul; ++i) {
			vector<int> A(2 * N + 1);
			int x = i;
			for (int j = 0; j <= 2 * N; ++j) {
				A[j] = x % 3;
				x /= 3;
			}
			int res1 = solve(N, A);
			int res2 = solve_easy(N, A);
			if (res1 != res2) {
				cout << "!" << endl;
			}
		}
	}
}
int main() {
	int N;
	cin >> N;
	vector<int> A(2 * N + 1);
	for (int i = 0; i <= 2 * N; ++i) {
		cin >> A[i];
	}
	int res = solve(N, A);
	cout << res << endl;
	return 0;
}