#include <cstdio>
#define ll long long
using namespace std;
const int NMAX = 50 ,L = 26 ;
ll f[NMAX] ;
ll p ;
ll nrzero(ll n){
    int nr0 = 0 ;
    while (n >= 5){
        nr0 += n / 5 ;
        n /= 5 ;
    }
    return nr0 ;
}
void cautbin(ll x){
    if (x == 0){
        printf("1") ;
        return ;
    }
    ll r = 0 , pas = 1 << L ;
    while (pas != 0){
        if (nrzero(r + pas) < p)
            r += pas ;
        pas /= 2 ;
    }
    r ++ ;
    if (nrzero(r) != p)
        r = -1 ;
    printf("%lld",r) ;
}
int main()
{
    freopen("fact.in","r",stdin) ;
    freopen("fact.out","w",stdout) ;
    scanf("%lld",&p) ;
    cautbin(p) ;
    return 0;
}