#include<atcoder/all>
using namespace atcoder;

#include <bits/stdc++.h>
template<class T> inline bool chmin(T&a, T b){if(a > b){a = b; return true;}else{return false;}}
template<class T> inline bool chmax(T&a, T b){if(a < b){a = b; return true;}else{return false;}}
#define ll long long
#define double long double
#define rep(i,n) for(int i=0;i<(n);i++)
#define REP(i,n) for(int i=1;i<=(n);i++)
#define mod (ll)(1e9+7)
#define inf (ll)(3e18+7)
#define eps (double)(1e-9)
#define pi (double) acos(-1)
#define all(x) x.begin(),x.end()
#define rall(x) x.rbegin(),x.rend()
using namespace std;

int main() {
    int n;
    cin >> n;

    vector<int> a(2 * n + 1);
    rep(i, 2 * n + 1)cin >> a[i];

    vector<int> a_(2 * n - 1);
    rep(i, 2 * n - 1) {
        a_[i] = 0;

        if(a[i] == 0 && a[i+1] == 1 && a[i+2] == 2)a_[i] = 1;
        if(a[i] == 1 && a[i+1] == 2 && a[i+2] == 0)a_[i] = 1;
        if(a[i] == 2 && a[i+1] == 0 && a[i+2] == 1)a_[i] = 1;

        if(a[i] == 0 && a[i+1] == 2 && a[i+2] == 1)a_[i] = 2;
        if(a[i] == 1 && a[i+1] == 0 && a[i+2] == 2)a_[i] = 2;
        if(a[i] == 2 && a[i+1] == 1 && a[i+2] == 0)a_[i] = 2;
    }

    bool f1 = true, f2 = true;
    rep(i, 2 * n - 1) {
        if(i % 2 == 0 && i/2 % 2 == 0 && a_[i] != 1)f1 = false;
        if(i % 2 == 0 && i/2 % 2 == 1 && a_[i] != 2)f1 = false;
        if(i % 2 == 1 && a_[i] != 0)f1 = false;

        if(i % 2 == 0 && i/2 % 2 == 0 && a_[i] != 2)f2 = false;
        if(i % 2 == 0 && i/2 % 2 == 1 && a_[i] != 1)f2 = false;
        if(i % 2 == 1 && a_[i] != 0)f2 = false;
    }

    if(f1 && n % 2 == 1)cout << 1 << endl;
    else if(f1 && n % 2 == 0)cout << 2 << endl;
    else if(f2 && n % 2 == 1)cout << 2 << endl;
    else if(f2 && n % 2 == 0)cout << 1 << endl;
    else cout << 0 << endl;
}