精度？

#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
ll a[7000001],n,l,k;
long double fg=99999999999.9,nt;
long double getfc(ll mul){
    long double avg=0,fc=0;
    for(int i=1;i<=n;i++){
        a[i]*=mul;avg+=a[i];
    }
    avg/=n;
    for(int i=1;i<=n;i++){
        fc+=(a[i]-avg)*(a[i]-avg);
    }
    fc/=n;
    for(int i=1;i<=n;i++)a[i]/=mul;
    return fc;
}
int main(){
    cin>>n>>k; 
    for(int i=1;i<=n;i++){
        cin>>a[i];
    }
    if(getfc(10)==0){
        cout<<"No answer!";return 0;
    }
    nt=getfc(1);
    cout<<(long long)(sqrt(k/nt));
}