#pragma GCC target("avx2")
#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")

#include <bits/stdc++.h>

using namespace std;

int main() {
	int N;
	scanf("%d", &N);

	bitset<200010> bit_0, bit_1, bit_2;

	int a;
	for(int i = 0; i < 2 * N + 1; i++) {
		scanf("%d", &a);
		// cout << a << endl;
		if(a == 0) {
			bit_0.set(i);
		} else if(a == 1) {
			bit_1.set(i);
		} else {
			bit_2.set(i);
		}
	}

	// cout << -1 << " 0 " << bit_0.any() << endl;
	// cout << -1 << " 1 " << bit_1.any() << endl;
	// cout << -1 << " 2 " << bit_2.any() << endl;
	bitset<200010> new_bit_0, new_bit_1, new_bit_2, bit_01, bit_10;
	for(int i = 0; i < N; i++) {
		bit_01 = (bit_0 & (bit_1 >> 1));
		new_bit_1 = (bit_01 & (bit_2 >> 2)) |
		            (bit_1 & (bit_2 >> 1) & (bit_0 >> 2)) |
		            (bit_2 & (bit_01 >> 1));
		bit_10 = (bit_1 & (bit_0 >> 1));
		new_bit_2 = (bit_0 & (bit_2 >> 1) & (bit_1 >> 2)) |
		            (bit_2 & (bit_10 >> 1)) |
		            (bit_10 & (bit_2 >> 2));
		swap(bit_1, new_bit_1);
		swap(bit_2, new_bit_2);
		bit_0 = (bit_1 ^ bit_2).flip();
	}

	if(bit_1.any())
		putchar('1');
	else if(bit_2.any())
		putchar('2');
	else
		putchar('0');

	return 0;
}