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#include <bits/stdc++.h>
#define int long long 
#pragma GCC optmize ("O3")
using namespace std;

int n, l, u, sf;
double mx, a[30009], c[30009];

signed main(){
    ifstream cin("secv3.in");
    ofstream cout("secv3.out");
    cin >> n >> u >> l;
    for(int i=1;i <= n;i++){
        cin >> c[i];c[i] += c[i - 1];
    }
    for(int i=1;i <= n;i++){
        cin >> a[i];a[i]=a[i - 1] + a[i];
    }
    for(int i=1;i <= n - u + 1;i++){
        for(int j=i + u - 1, sf=min(n, i + min(l - 1, u + 1000));j <= sf;j++){
            if(c[j] - c[i - 1] > mx * (a[j] - a[i - 1])){
                mx=(c[j] - c[i - 1]) / (a[j] - a[i - 1]);
            }
        }
    }
    cout << fixed << setprecision(2) << mx;
    return 0;
}