#include <iostream>
#include <set>
#include <vector>

using namespace std;
/*int solve(vector<int> v){
    while(v.size()>1){
        vector<int> u;
        for(int i=1;i<v.size() - 1;i++){
            if(v[i - 1]==0 && v[i]==1 && v[i + 1]==2) u.push_back(1);
            else if(v[i - 1]==1 && v[i]==2 && v[i + 1]==0) u.push_back(1);
            else if(v[i - 1]==2 && v[i]==0 && v[i + 1]==1) u.push_back(1);
            else if(v[i - 1]==2 && v[i]==1 && v[i + 1]==0) u.push_back(2);
            else if(v[i - 1]==1 && v[i]==0 && v[i + 1]==2) u.push_back(2);
            else if(v[i - 1]==0 && v[i]==2 && v[i + 1]==1) u.push_back(2);
            else u.push_back(0);
        }
        swap(u,v);
    }
    return v[0];
}*/

int main(){
    /*set<vector<int>> s;
    int i,n; cin >> n;
    int num = 1;
    for(i=0;i<n;i++) num *= 3;
    for(i=0;i<num;i++){
        int x = i;
        vector<int> v;
        while(v.size()<n){
            v.push_back(x%3); x /= 3;
        }
        int y = solve(v);
        if(y==2) s.insert(v);
    }
    for(auto v:s){
        for(int x:v) cout << x << " ";
        cout << endl;
    }*/
    int i,j,n; cin >> n;
    n *= 2; n++;
    vector<int> a(n),v(4),u(4),l,r;
    for(i=0;i<n;i++) cin >> a[i];
    v[0] = 0,v[1] = 1,v[2] = 2,v[3] = 1;
    u[0] = 0,u[1] = 2,u[2] = 1,u[3] = 2;
    set<vector<int>> o,t;
    while(l.size()<n){
        for(i=0;i<4;i++) l.push_back(v[i]);
        for(i=0;i<4;i++) r.push_back(u[i]);
    }
    while(l.size()>n) l.pop_back(),r.pop_back();
    if(n%4==1){
        for(i=0;i<3;i++){
            o.insert(r); t.insert(l);
            for(j=0;j<n;j++){
                (l[j] += 1) %= 3; (r[j] += 1) %= 3;
            }
        }
    }else{
        for(i=0;i<3;i++){
            o.insert(l); t.insert(r);
            for(j=0;j<n;j++){
                (l[j] += 1) %= 3; (r[j] += 1) %= 3;
            }
        }
    }
    /*for(auto v:o){
        for(int x:v) cout << x << " ";
        cout << endl;
    }
    for(auto v:t){
        for(int x:v) cout << x << " ";
        cout << endl;
    }
    return 0;*/
    if(o.count(a)) cout << 1 << endl;
    else if(t.count(a)) cout << 2 << endl;
    else cout << 0 << endl;
}