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#include <cstdion>
#include <algorithm>
using namespace std;
struct mooncake{
    double store;   //庫存量
    double sell;    //總售價
    double price;   //單價
}cake[1010];
bool cmp(mooncake a,mooncake b){    //按單價從高到低排序
    return a.price>b.price;
}
int main(){
    int n;
    double D;
    scanf("%d%lf",%n,%D);
    for(int i=0;i<n;i++){
        scanf("%lf",&cake[i].store);
    }
    for(int i=0;i<n;i++){
        scanf("%lf",&cake[i].sell);
        cake[i].price=cake[i].sell/cake[i].store;   //計算單價
        
    }
    
    sort(cake,cake+n,cmp);  //按單價從高到低排序
    double ans=0;   //收益
    for(int i=0;i<n;i++){
        if(cake[i].store<=D){   //若是需求量高於月餅庫存量
            D-=cake[i].store;      //第i種月餅所有賣出
            ans+=cake[i].sell;
        }else{
            ans+=cake[i].price*D    //只賣出剩餘需求量的月餅
            break;
        }
    }
    printf("%.2f\n",ans);
    return 0;
}

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