#include<stdio.h>
#include<time.h>
#include<math.h>
 
using namespace std;
 
int main()
{
 
    long long p, i=0, n=0, k=0;
    int j;
    FILE *ifp, *ofp;
    ifp = fopen("fact.in", "r");
    ofp = fopen("fact.out", "w");
     
    fscanf(ifp, "%Ld", &p);
     
    n = p*5-p;
    while (n%5!=0)
        n++;
         
    for (j=1;j<=14;j++)
        k=k+( n / (long long)pow(5,j) );
         
    while (k<p)
    {
        n+=5;
        for (j=1;j<=14;j++)
            if (n % (long long)pow(5,j)==0)
                k++;
    }
     
     
    if (p==0)
        fprintf(ofp, "%d", 1);
    else
        if (k>p)
            fprintf(ofp, "%d", -1);
        else
            fprintf(ofp, "%Ld", n);
 
    return 0;
}