#include<stdio.h>
int main()
{
	long long ci,i=0,p,num=0,x=100,c=1,put=25;
	freopen ("fact.in","r",stdin);
	freopen ("fact.out","w",stdout);
	scanf("%lld",&p);
	while (num<p)
	{
		i=i+5;
		if(i>=x) { x*=10; c++; }
		num+=c;
		if(i==put) { num++; put*=5;}
		if (num==p)
			{ printf("%lld",i); break;}
		else if(num>p)
			{ printf("-1"); break;}
	}
	return 0;
}