//
//  main.cpp
//  Alex
//
//  Created by Hurjui Alexandru Mihai on 02/11/2018.
//  Copyright © 2018 Hurjui Alexandru Mihai. All rights reserved.
//

#include <fstream>
using namespace std;

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

int main()
{
    int p, n, nr = 0, i, i2;
    fin >> p;
    if (p == 0)
        fout << 1;
    else
    {
        i = 5;
        while (nr < p)
        {
            i2 = i;
            while (i%5==0)
            {
                i=i/5;
                nr++;
            }
            i = i2 + 5;
        }
        if (nr == p)
            fout << i-5;
        else
            fout << -1;
    }
    return 0;
}