#include <bits/stdc++.h>
using namespace std;
// #include <atcoder/all>
// using namespace atcoder;
// using mint = atcoder::static_modint<998244353>;
// using mint = atcoder::static_modint<1000000007>;
using ld = long double;
using ll = long long;
#define mp(a,b) make_pair(a,b)
#define rep(i,s,n) for(int i=s; i<(int)n; i++)
const vector<int> dx{1,0,-1,0},dy{0,1,0,-1};

int main(){
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    int n;cin >> n;
    ll a=1;
    ll findzero=false;
    rep(i,0,n){
        ll p;cin >> p;
        if(p==0)findzero=true;
        p%=9;
        a*=p;
        a%=9;
    }
    if(a==0 && !findzero)a+=9;
    cout << a << "\n";
}