//g++ 1.cpp -std=c++14 -O2 -I .
#include <bits/stdc++.h>
using namespace std;

#include <atcoder/all>
using namespace atcoder;

using ll = long long;
using ld = long double;

using vi = vector<int>;
using vvi = vector<vi>;
using vll = vector<ll>;
using vvll = vector<vll>;
using vld = vector<ld>;
using vvld = vector<vld>;

#define fi first
#define se second
#define pb push_back
#define pq_big(T) priority_queue<T,vector<T>,less<T>>
#define pq_small(T) priority_queue<T,vector<T>,greater<T>>
#define all(a) a.begin(),a.end()
#define rep(i,start,end) for(ll i=start;i<(ll)(end);i++)
#define per(i,start,end) for(ll i=start;i>=(ll)(end);i--)
#define uniq(a) sort(all(a));a.erase(unique(all(a)),a.end())

vvll com(3,vll(3));
 
ll COM(int n,int k){
  if(k==0)return 1;
  ll x=1;
  rep(i,0,100){
    int a=n%3,b=k%3;
    x*=com[a][b];
    n/=3,k/=3;
  }
  return x%3;
}

int main(){
  ios::sync_with_stdio(false);
  cin.tie(nullptr);

  com[0][0]=1,com[0][1]=0,com[0][2]=0;
  com[1][0]=1,com[1][1]=1,com[1][2]=0;
  com[2][0]=1,com[2][1]=2,com[2][2]=1;

  int n;
  cin>>n;

  vi a(2*n+1);
  rep(i,0,2*n+1){
    cin>>a[i];
  }

  rep(i,0,2*n){
    if(a[i]==a[i+1]){
      cout<<0<<endl;
      return 0;
    }
  }

  int ans=0;
  rep(i,0,n+1){
    int nw=a[2*i];
    nw*=1+i%2;
    nw*=COM(n,i);
    ans+=nw%3;
  }

  cout<<ans%3<<endl;
}