#include<bits/stdc++.h>
using namespace std;

void solve(){
    int t,q;
    cin>>t>>q;
    
    const long double EPS = 1e-18, INF = 1e12, EPS2 = 1e-18;
    vector<int> n(t),sump(t),sumc(t),currc(t);
    long long tot=0;
    vector<vector<int>> p(t),c(t);
    long double currsumqb=0,currsumqf=0,currsumsqrtc=0;
    vector<long double> val,sumsqrtc,sumqb,sumqf;
    
    struct Update{
        long double t;
        int mode; // 0 = sqrtc upd, 1 = qb upd, 2 = qf upd
        long double x;
    };
    vector<Update> tmp;
    
    auto addqb = [&](long double l,long double r,long double val){
        tmp.push_back({l,1,val});
        tmp.push_back({r,1,-val});
    };
    
    auto addqf = [&](long double l,long double r,long double val){
        tmp.push_back({l,2,val});
        tmp.push_back({r,2,-val});
    };
    
    auto addsqrtc = [&](long double l,long double r,long double val){
        tmp.push_back({l,0,val});
        tmp.push_back({r,0,-val});
    };
    
    for(int i=0;i<t;i++){
        cin>>n[i];
        p[i].resize(n[i]);
        c[i].resize(n[i]);
        for(int j=0;j<n[i];j++){
            cin>>c[i][j];
            sumc[i]+=c[i][j];
        }
        tot+=sumc[i];
        for(int j=0;j<n[i];j++){
            cin>>p[i][j];
            sump[i]+=p[i][j];
        }
        
        
        vector<pair<long double,int>> soglie;
        long double qb=0,qf=0,qq=0;
        
        for(int j=0;j<n[i];j++){
            long double pp = (long double)(p[i][j])/sump[i];
            long double cc = c[i][j];
            
            if(sumc[i]-cc/pp<-EPS){
                //cout<<"all'inizio "<<j<<" e' attivo\n";
                soglie.push_back({cc/pp,j});
                currc[i]+=c[i][j];
                qf+=cc/sumc[i]-pp;
                qq+=pp;
            }
        }
        qb = sumc[i];
        
        addqb(-INF,-currc[i]/(qb*qb),qb);
        addqf(-INF,-currc[i]/(qb*qb),qf);
        
        //cout<<"tra "<<-INF<<" e "<<-currc[i]/(qb*qb)<<" ho "<<qb<<" e "<<qf<<"\n";
        
        soglie.push_back({qb,-1});
        sort(soglie.begin(),soglie.end());
        
        for(int j=1;j<soglie.size();j++){
            
            
            addsqrtc(-currc[i]/(soglie[j-1].first*soglie[j-1].first),-currc[i]/(soglie[j].first*soglie[j].first),sqrt(currc[i]));
            addqf(-currc[i]/(soglie[j-1].first*soglie[j-1].first),-currc[i]/(soglie[j].first*soglie[j].first),-qq);
            
            //cout<<"tra "<<-currc[i]/(soglie[j-1].first*soglie[j-1].first)<<" e "<<-currc[i]/(soglie[j].first*soglie[j].first)<<" ho "<<sqrt(currc[i])<<" sqrt e "<<-qq<<"\n";
            
            
            qb = soglie[j].first;
            qf = 0;
            for(int k=0;k<n[i];k++){
                long double pp = (long double)(p[i][k])/sump[i];
                long double cc = c[i][k];
                
                if(k==soglie[j].second)qq-=pp;
                if(qb-cc/pp<-EPS){
                    qf+=cc/qb-pp;
                }
            }
            
            long double v1 = -currc[i]/(qb*qb);
            currc[i]-=c[i][soglie[j].second];
            long double v2 = -currc[i]/(qb*qb);
            
            
            //cout<<"tra "<<v1<<" e "<<v2<<" ho "<<qb<<" e "<<qf<<"\n";
            addqb(v1,v2,qb);
            addqf(v1,v2,qf);
        }
    }
    sort(tmp.begin(),tmp.end(),[](auto x,auto y){return x.t<y.t;});
    
    
    for(int i=0;i<tmp.size();i++){
        
        int ind = i;
        auto t = tmp[i].t;
        while(ind<tmp.size() && abs(tmp[ind].t-tmp[i].t)<EPS){
            if(tmp[ind].mode==0){
                currsumsqrtc+=tmp[ind].x;
            }else if(tmp[ind].mode==1){
                currsumqb+=tmp[ind].x;
            }else{
                currsumqf+=tmp[ind].x;
            }
            ind++;
        }
        
        
        //cout<<t<<" "<<currsumsqrtc<<" "<<currsumqb<<" "<<currsumqf<<"\n";
        val.push_back(t);
        sumsqrtc.push_back(currsumsqrtc);
        sumqb.push_back(currsumqb);
        sumqf.push_back(currsumqf);
        i = ind-1;
    }
    
    for(int i=0;i<q;i++){
        long long x;
        cin>>x;
        
        x+=tot;
        int low = 0, up = val.size();
        
        while(up-low>1){
            int mid = (up+low)/2;
            
            if(sumqb[mid]+sumsqrtc[mid]/sqrt(-val[mid])<=x){
                low=mid;
            }else{
                up=mid;
            }
        }
        //cout<<low<<" ecco\n";
        
        if(low==val.size()-1){
            cout<<"0.0\n";
        }else{
            long double llow = val[low], uup = val[low+1];
            
            while(uup-llow>EPS2){
                long double mid = (uup+llow)/2.0;
                
                if(sumqb[low]+sumsqrtc[low]/sqrt(-mid)<=x){
                    llow=mid;
                }else{
                    uup=mid;
                }
            }
            
            cout<<setprecision(20)<<2.0*(sumqf[low]+sumsqrtc[low]*sqrt(-llow))<<"\n";
        }
    }
}

int main(){
    ios::sync_with_stdio(false);
    cin.tie(0);
    
    int t=1;
    //cin>>t;
    for(int i=1;i<=t;i++)solve();
    
    return 0;
}