Rice

#include <bits/stdc++.h>
using namespace std;
using pii=pair<double,double>;
int main(){
    int n,x,y,w;
    double ppq,price,p,q;
    scanf("%d",&n);
    priority_queue<pii,vector<pii>,greater<pii>> pq;

    for(int i=0;i<n;i++){
        scanf("%lf%lf",&p,&q);
        ppq=p/q;
        pq.push({ppq,q});
    }

    scanf("%d",&n);
    for(int i=0;i<n;i++){
        price=0;
        scanf("%d",&w);
        while(w!=0){
            double P=pq.top().first;
            double Q=pq.top().second;
            pq.pop();
            if(Q>=w){
                Q=Q-w;
                price+=P*w;
                if(Q!=0)
                pq.push({P,Q});
                break;
            }else{
                price+=P*Q;
                w-=Q;
            }
        }
        printf("%.3lf\n",price);
    }
}