#include <stdio.h>

using namespace std;

long factor(int a)
{
    if(a>1)
        return(a*factor(a-1));
    else return (1);
}

int main()
{
    int n,p,sz,szj,num;
    FILE *f=fopen("fact.in","r");
    FILE *g=fopen("fact.out","w");
    fscanf(f,"%i",&p);
    n=1;
    sz=0;
    int talalt=0;
    while(talalt!=1)
    {
        num=factor(n);
        do
        {
            szj=num%10;
            if(szj==0)
                sz++;
            num=num/10;
        }while(szj==0);
        if(sz==p)
        {
            talalt=1;
        }
        else n++;
    }
    if(talalt==1) fprintf(g,"%i",n);
    else fprintf(g,"-1");
    return 0;
}