#include <stdio.h>
#include <stdlib.h>
long long n;
int main()
{
    FILE *f,*g;
    f=fopen("fact.in","r");
    g=fopen("fact.out","w");
    int p,ok,nr,x,i;
    fscanf(f,"%d",&p);
    n=5;
    ok=0;
    nr=0;
    if(p==0)
    fprintf(g,"%d\n",1);
    else
    {
    while(nr<p)
    {
        nr=0;
        for(i=5;i<=n;i+=5)
        {
            x=i;
            while(x%5==0&&x>1)
            {
             nr++;
             x/=5;
            }
        }
        if(nr<p)
        n+=5;
    }
    if(nr>p)
    fprintf(g,"%d\n",-1);
    else
    {
        fprintf(g,"%lld\n",n);
    }
   }
    return 0;
}