#include <iostream>
#include <fstream>
using namespace std;
long long n,p,i,x,k;
int main()
{
    freopen("fact.in","r",stdin);
    freopen("fact.out","w",stdout);
    cin>>p;
    if(p==0) {cout<<1;return 0;}
    k=0;
    for(i=5;k<p;i+=5)
    {
        x=i;
        while(x%5==0) x/=5,k++;
    }
    if(k==p) cout<<i-5;
    else cout<<-1;
    return 0;
}