#include <iostream>
#include <fstream>

using namespace std;

int main()
{
    ifstream f("fact.in");
    ofstream g("fact.out");
    long int p;
    long int i = 0;
    long db = 0;
    f >> p;
    if(p==0) {
        i = 1;
    }
    else {
    while (db<p) {
            i = i + 5;
            long j = i;
            while((j % 5)==0) {
                db++;
                j = j/5;
            }

    }}
    if(db==p) {
            g << i; }
    else {
        g << "-1" ;
    }
    return 0;
}