#include <cstdio>
int p,put = 1,i;
int main()
{
	freopen("fact.in","r",stdin);
	freopen("fact.out","w",stdout);
	scanf("%d",&p);
	if(p == 0)
		printf("1");
	else if(p == 5)
		printf("-1");
	else if(p < 5)
		printf("%d",p*5);
	else if(p > 5)
	{
		for(i = 1;;i++)
		{
			put *= 5;
			if(put * 5 > p)
				break;
		}
		printf("%d",p*5 - put);
	}
	return 0;	
}