#include <bits/stdc++.h>
using namespace std;
struct oil{
    int w,v;
    double s;
}a[1000005];
bool cmp(oil a,oil b) {
    return a.s>b.s;
}
int main(){
	freopen("mouse.in","r",stdin);
	freopen("mouse.out","w",stdout);
    int n,m;
    cin>>n>>m;
    for(int i=0;i<n;i++) {
        cin>>a[i].w>>a[i].v;
        a[i].s=(double)a[i].v/a[i].w; 
    }
    sort(a,a+n,cmp);
    double vmax=0;
    for(int i=0;i<n&&m>0;i++) {
        if (a[i].w<=m){
            vmax+=a[i].v;
            m-=a[i].w;
        }else{
            vmax+=a[i].s*m;
            break; 
        }
    }
    cout<<fixed<<setprecision(4)<<vmax;
    return 0;
}

在编译器上不会报错，但在提交时会报错

真就离谱