#include<stdio.h>  
FILE *in=fopen("fact.in","r"),*out=fopen("fact.out","w");  
long int p,i=0,j=0,aux;  
int main()  
{  
	fscanf(in,"%ld",&p);  
	if(!p)fprintf(out,"1");  
	else  
	{  
		while(i<p)  
		{  
			j+=5;aux=j;  
			while(aux%5==0)  
			{  
				aux/=5;  
				i++;  
			}  
		}
	}
if(i>p)fprintf(out,"-1")l;
else fprintf(out,"%ld",j);  
}  
fcloseall();  
return 0;  
}