#include <bits/stdc++.h>
using namespace std;
#define ll long long
void harmasba(int num)
{   if(num == 0){
    return;
    }
    int x = num % 3;
    num /= 3;
    harmasba(num);

    cout << x;
}
int main()
{
    int n; cin >> n;
    vector <int> S(n);
    for(int i = 0; i < n; i++) cin >> S[i];
    ll ans = 0, num = 0;
    for(int i = 0; i < n; i++){
        if(S[i] >= 0 && S[i] <= 2){
            ans++;
            num = num*3 + S[i];
        }
        else if(S[i] == 3){
            ans--;
            num /= 3;
        }
        else if(S[i] == 4){
            num--;
        }
        else num++;
    }
    cout << ans << "\n";
    harmasba(num);
    return 0;
}