9542

#pragma GCC optimize("O3")
#include <bits/stdc++.h>
using namespace std;

#define int long long
#define io ios_base::sync_with_stdio(0); cin.tie(0)
#define pb push_back
#define F first
#define S second
#define endl '\n'
const int N = 1e6 + 5;


signed main()
{
    io;

    int n;
    cin >> n;
    vector<int> v;
    for(int i = 2; i <= 9; i++){
        while(n % i == 0){
            v.pb(i);
            n /= i;
        }
    }
    if(n != 1){
        cout << "-1";
        return 0;
    }
    reverse(v.begin() , v.end());
    for(int i : v)
        cout << i;
}