#include <bits/stdc++.h>
std::ifstream fin("secv3.in");
std::ofstream fout("secv3.out");
int n, l, u, cnt;
double left, right, mid, sum;
std::pair<double, double> list[30005];
double numbers[30005];
std::queue<double> q;
bool check(double val);
int main()
{
    fin>>n>>l>>u;
    for(int i=1; i<=n; ++i) fin>>list[i].first;
    for(int i=1; i<=n; ++i) fin>>list[i].second;
    left=0.0, right=1000.0;
    for(int k=1; k<=500; ++k){
        mid=(left+right)/2;
        if(check(mid)) left=mid;
        else right=mid;
    }
    fout<<std::fixed<<std::setprecision(2)<<left;
    return 0;
}
bool check(double val){
    sum=0.0; cnt=0; bool done=false;
    for(int i=1; i<=n; ++i)  numbers[i]=list[i].first-list[i].second*val;
    for(int i=1; i<l; ++i) {
        q.push(numbers[i]);
        sum+=numbers[i];
        ++cnt;
    }
    for(int i=l; i<=n; ++i){
        q.push(numbers[i]);
        sum+=numbers[i];
        ++cnt;
        if(cnt>u){
            --cnt;
            sum-=q.front();
            q.pop();
        }
        while(cnt>l && sum<0 && q.front()<0){
            --cnt;
            sum-=q.front();
            q.pop();
        }
        if(sum>=0) {done=true; break;}
    }
    while(!q.empty()) q.pop();
    return done;
}