#include<stdio.h>
long int n,p,aux,x=0,i=0;
int c,c1;
int main ()
{
FILE*f=fopen("fact.in","r");
FILE*g=fopen("fact.out","w");
fscanf(f,"%ld",&p);

if (p==0) fprintf(g,"1");
 else {
while (x<p)
    {i=i+5;aux=i;
     while (aux)
       {if (aux%5==0) {x++;aux=aux/5;}
	else break;}
    }
if (x==p) fprintf(g,"%ld",i);
    else fprintf(g,"-1");
       }
fclose(f);
fclose(g);
return 0;         
}