错两个点，调了半天没找到 hack……

#include<bits/stdc++.h>
using namespace std;
#define int unsigned long long
int n,m;
int p[300500];
int ans=0;
bool check(int x){
	int nowm=m;
	for(int i=1;i<=n;i++){
//		double mn=p[i]*pow(ceil(sqrt(x*1.0/p[i])),2);
		double wenhao=floor((x*1.0/p[i]+1)/2.0);
		double mn=pow(wenhao,2)*p[i];
//		int sxsd=mn;
//		printf("%lld %lld %lld\n",x,sxsd,nowm);
		if(nowm<mn) return false;
		else{
			nowm-=mn;
		}
	}
//	puts("");
	return true;
}
signed main(){
//	cout<<log2(1e18);
	cin>>n>>m;
	for(int i=1;i<=n;i++){
		cin>>p[i];
	}
	int l=0,r=m;
	while(l<=r){
		int mid=l+((r-l)>>1);
		if(check(mid)){
			ans=mid;
			l=mid+1;
		}else{
			r=mid-1;
		}
	}
	int sum=0;
	int nowm=m;
	for(int i=1;i<=n;i++){
		double wenhao=floor((ans*1.0/p[i]+1)/2.0);
		double mn=pow(wenhao,2)*p[i];
		nowm-=mn;
		sum+=wenhao;
	}
//	printf("%lld %lld %lld\n",ans,sum,nowm);
	ans++;
	for(int i=1;i<=n;i++){
		if((ans*1.0/p[i]+1)/2.0==signed((ans*1.0/p[i]+1)/2.0)){
			if(nowm>=ans){
				sum++;
			}
		}
	}
	printf("%lld\n",sum);
	return 0;
}