#include <stdio.h>

int v[15]={0,5,25,125,625,3125,15625,78125,390625,1953125,9765625,48828125,244140625,1220703125,999999999};
int p,c,n,i;

int main ()
{
    freopen ("fact.in","r",stdin);
    freopen ("fact.out","w",stdout);
    
    scanf ("%d",&p);
    
    if (p>=30000000) {c=30000000;n=120000010;}
    if (p>=50000000) {c=50000000;n=200000010;}
    if (p>=60000000) {c=60000000;n=240000020;}
    if (p>=70000000) {c=70000000;n=280000015;}
    if (p>=80000000) {c=80000000;n=320000015;}
    if (p>=90000000) {c=90000000;n=360000015;}
    
    while (c<p){
          n=n+5;
          for (i=1;i<=13;i++)
              if (n%v[i+1]!=0) {
                               c=c+i;
                               break;
                               }
          }
          
    if (p==0) printf ("1");
    else if (c==p) printf ("%d",n);
    else printf ("-1");
    
    return 0;
}