#include<bits/stdc++.h>
#define ll long long int
using namespace std;
ll panu(ll n)
{
    if(n == 0)
        return 10;
    if(n >= 1 && n <= 9)
        return n;
    int i;
    stack<ll>d;
    for(i=9;i>=2 && n > 1;i--)
    {
        while(n%i == 0)
        {
            d.push(i);
            n = n/i;
        }
    }
    if(n != 1)
        return -1;
    ll k = 0;
    while(!d.empty())
    {
        k = k*10 + d.top();
        d.pop();
    }

    return k;
}
int main()
{
    ll n;
    cin >> n;

    cout << panu(n) << "\n";

    return 0;
}

Edited by author 27.01.2020 21:17