// 高速化愚直解　想定 TLE

#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;

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

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

// for i in range(N):
//     l = 2 * (N - i) - 1
//     bit_10 = bit_1 & (bit_0 >> 1)
//     new_bit_1 = 0
//     new_bit_1 |= bit_0 & (bit_2 >> 1) & (bit_1 >> 2)
//     new_bit_1 |= bit_2 & (bit_10 >> 1)
//     new_bit_1 |= bit_10 & (bit_2 >> 2)
//     bit_01 = bit_0 & (bit_1 >> 1)
//     new_bit_2 = 0
//     new_bit_2 |= bit_01 & (bit_2 >> 2)
//     new_bit_2 |= bit_1 & (bit_2 >> 1) & (bit_0 >> 2)
//     new_bit_2 |= bit_2 & (bit_01 >> 1)
//     bit_1 = new_bit_1
//     bit_2 = new_bit_2
//     bit_0 = (-1) ^ bit_1 ^ bit_2

// if bit_1:
//     print(1)
// elif bit_2:
//     print(2)
// else:
//     print(0)