#include <bits/stdc++.h>
//#include <atcoder/all>
using namespace std;
//using namespace atcoder;
//using mint = modint1000000007;
//const int mod = 1000000007;
//using mint = modint998244353;
//const int mod = 998244353;
//const int INF = 1e9;
//const long long LINF = 1e18;
//const bool debug = false;
#define rep(i, n) for (int i = 0; i < (n); ++i)
#define rep2(i,l,r)for(int i=(l);i<(r);++i)
#define rrep(i, n) for (int i = (n-1); i >= 0; --i)
#define rrep2(i,l,r)for(int i=(r-1);i>=(l);--i)
#define all(x) (x).begin(),(x).end()
#define allR(x) (x).rbegin(),(x).rend()
#define endl "\n"
#define P pair<int,int>
template<typename A, typename B> inline bool chmax(A & a, const B & b) { if (a < b) { a = b; return true; } return false; }
template<typename A, typename B> inline bool chmin(A & a, const B & b) { if (a > b) { a = b; return true; } return false; }
bool check0(vector<int>v) {
	rep(i, v.size()) {
		if ((1 == i % 4) || (3 == i % 4)) {
			if (0 != v[i])return false;
		}
		else if (0 == i % 4) {
			if (1 != v[i])return false;
		}
		else {
			if (2 != v[i])return false;
		}
	}
	return true;
}
bool check1(vector<int>v) {
	rep(i, v.size()) {
		if ((1 == i % 4) || (3 == i % 4)) {
			if (0 != v[i])return false;
		}
		else if (2 == i % 4) {
			if (1 != v[i])return false;
		}
		else {
			if (2 != v[i])return false;
		}
	}
	return true;
}
int main() {
	ios::sync_with_stdio(false);
	cin.tie(nullptr);
	int n; cin >> n;
	vector<int>a(2 * n + 1);
	rep(i, a.size())cin >> a[i];
	{
		vector<int>sub;
		rep(i, a.size() - 2) {
			if ((0 == a[i]) && (1 == a[i + 1]) && (2 == a[i + 2])) sub.push_back(1);
			else if ((1 == a[i]) && (2 == a[i + 1]) && (0 == a[i + 2])) sub.push_back(1);
			else if ((2 == a[i]) && (0 == a[i + 1]) && (1 == a[i + 2])) sub.push_back(1);
			else if ((2 == a[i]) && (1 == a[i + 1]) && (0 == a[i + 2])) sub.push_back(2);
			else if ((1 == a[i]) && (0 == a[i + 1]) && (2 == a[i + 2])) sub.push_back(2);
			else if ((0 == a[i]) && (2 == a[i + 1]) && (1 == a[i + 2])) sub.push_back(2);
			else sub.push_back(0);
		}
		swap(sub, a);
	}
	if (0 == ((a.size() - 1) / 2) % 2) {
		if (check0(a))cout << 1 << endl;
		else if (check1(a)) cout << 2 << endl;
		else cout << 0 << endl;
	}
	else {
		if (check1(a))cout << 1 << endl;
		else if (check0(a)) cout << 2 << endl;
		else cout << 0 << endl;
	}
	return 0;
}