#include <bits/stdc++.h>
#define nmax 2005
#define valmax 3505

using namespace std;

ifstream fin ("divmax.in");
ofstream fout ("divmax.out");

short int n, x, maxim;
pair <short int, short int> f[valmax];
vector <short int> maxdiv;

int putere( int p)
{
    int rez = 1;
    while ( p-- )
        rez *= 10;
    return rez;
}

bool cmp (int a, int b)
{
    int ca = a, cb = b, ka = 0, kb = 0;
    while ( ca/=10 )
        ka++;
    while ( cb/=10 )
        kb++;
    while ( a/putere(ka)%10 == b/putere(kb)%10 && ka >= 1 && kb >= 1 )
    {
        ka--;
        kb--;
    }
    return a/putere(ka)%10 > b/putere(kb)%10;
}

void ciur( int lim )
{
    for ( int i = 2; i <= (int)sqrt(lim); ++i )
        if ( !f[i].first )
        {
            f[i].second = i;
            for ( int j = 2*i; j <= lim; j += i )
                f[j] = {1, i};
        }
}

int main()
{
    ios::sync_with_stdio(false);
    cin.tie(NULL); cout.tie(NULL);
    ciur(3500);
    fin>>n;
    for ( int i = 1; i <= n; ++i )
    {
        fin>>x;
        maxdiv.push_back(f[x].second);
        maxim = max(f[x].second, maxim);

    }
    fout<<maxim<<'\n';
    sort(maxdiv.begin(), maxdiv.end(), cmp);
    for ( int i = 0; i < maxdiv.size(); ++i )
        fout<<maxdiv[i];
}