#include<cstdio>
int main(){
	freopen("fact.in","r",stdin);
	freopen("fact.out","w",stdout);
	long long p;
	scanf("%lld",&p);
	long long k=p,q=5,pas=5;
	if(p==0) {
		printf("1\n");
		return 0;}
	while(k>0){
		q=pas;
		while(q%5==0 && k>0){
			k--;
			q/=5;
		}
		if( k==0 && q!=1){
			printf("-1\n");
			return 0;
		}
		pas=pas+5;
	}
	printf("%lld",pas-5);
	return 0;
}