#include <iostream>
#include <vector>
#include <algorithm>

using namespace std;

int main()
{
    int Num = 0, ans = -2;

    cin >> Num;

    vector <int> fact;

    int n = 2;

    while (Num > 1)
    {
        if (n > 9) {
            ans = -1;
            break;
        }
        while (Num % n == 0) {
            Num /= n;
            fact.push_back(n);
        }
        n++;
    }

    sort(fact.begin(), fact.end());

    if (n < 10 & ans != -1)
    {
        ans = 0;
        for (int i = 0; i < fact.size(); i++) {
            //ans += fact.at(i) * (i*10);
            cout << fact[i];
        }
    }


    //cout << ans;
}