#include <iostream>
#include <set>
using namespace std;
int main()
{multiset<int> ms;
 int i, n;
 cin>>n;
 if(n==0) {cout<<10; return 0;}
 if(n==1) {cout<<1; return 0;}
 for(i=9; i>=2; i--)
   while(n%i==0)
        {ms.insert(i);
         n/=i;
        }

 if(n>1) {cout<<-1; return 0;}
 else
    for(multiset<int>::iterator it=ms.begin(); it!=ms.end(); it++)
        cout<<*it;
    return 0;
}
//---------------------------------------------------------------------------


Edited by author 08.11.2008 01:39