#include <iostream>
#include <cstdio>
using namespace std;
int n;
int L=28,r;
int numarzero(int n)
{
    int nr=0;
    while(n!=0)
    {
        nr=nr+n/5;
        n=n/5;
    }
    return nr;
}
 
int caut(int x)
{
    int pas;
    r=0;
    pas=1<<L;
    while(pas!=0)
    {
        if(numarzero(pas+r)<x)
            r+=pas;
        pas=pas/2;
    }
    r++;
    return r;
}
 
int main()
{
    freopen("fact.in","r",stdin);
    freopen("fact.out","w",stdout);
    scanf("%d", &n);
    r = caut(n);
    if(numarzero(r)!=n)
        printf("-1");
    else
        printf("%d", r);
 
    return 0;
}