#include<bits/stdc++.h>

using namespace std;
const int maxn=7e6+5;
double n,ans,sum,k,a[maxn],w;
signed main(){
	scanf("%lf%lf",&n,&k);
	for(int i=1;i<=n;++i)
		scanf("%lf",&a[i]),sum+=a[i];
	bool check=1;
	sum=sum*1.0/n;
	for(int i=2;i<=n;++i)
		check&=(a[i]==a[i-1]);
	for(int i=1;i<=n;++i)
		ans+=(a[i]-sum)*(a[i]-sum);
	if(ans<=0.1){
		printf("No answer!");
		return 0;
	}
	ans=ans*1.0/n;
	if(fabs(k*1.0/ans-int(k*1.0/ans)-0.5)<=0.05)	
		w=sqrt(k*1.0/ans);
	else
		w=sqrt(k*1.0/ans+0.5);
	if(fabs(w-int(w)-0.5)>0.05)
		w=w+0.5;
	w+=(int(w)==0);
	printf("%.0lf",w-0.5);
	return 0;
}