#include <vector>
#include <iostream>
#include <algorithm>
using namespace std;
int main() {
	int N;
	cin >> N;
	vector<int> A(2 * N + 1);
	for (int i = 0; i <= 2 * N; ++i) {
		cin >> A[i];
	}
	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;
		}
	}
	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 == s0) {
		cout << 1 << endl;
	}
	else if (B == s1) {
		cout << 2 << endl;
	}
	else {
		cout << 0 << endl;
	}
	return 0;
}