#include <stdio.h>

int put5(long unsigned int n)
{
    if(n<25)
        n=0;
    else
        while(n%5==0)
            n=n/5;
    return n;
}
int p;
long  int n;
int main()
{
    freopen("fact.in", "r", stdin);
    freopen("fact.out", "w", stdout);
    scanf("%d", &p);
    n=0;
    if(p==0)
    {
        n=1;
        printf("%ld",n);
    }
    else{
        while(p>0)
        {
            n+=5;
            if(put5(n)==1)
                p=p-2;
            else
                p--;

        }
        if(p==0)
            printf("%ld",n);
        else
        {
            n=-1;
            printf("%ld",n);
        }
    }

    return 0;
}