#include <cstdio>
#define ui unsigned int

inline int nrzero(int i)
{
	int t=0;
	while(i) t+=i/5, i/=5;
	return t;
}

int main()
{
	ui cnt, n, i, p, q;
	
	freopen("fact.in","r",stdin);
	freopen("fact.out","w",stdout);
	scanf("%d", &n);
	
	i=(1<<31);
	for(cnt=(1<<30);cnt;cnt>>=1)
		if(i-cnt>=1)
			if(nrzero(i-cnt)>=n) i-=cnt;
	
	if(nrzero(i)==n) printf("%d\n", i);
		else printf("-1\n");
	return 0;
}