#include<stdio.h>
#include<stdlib.h>

int VCost[30001] , VTimp[30001];

int main()
{
    int Lmax,Lmin,N,i,j,k;
    float Med,Max=0,Cost,Timp;

    FILE *fp;
    fp = fopen("secv3.in","r");
    FILE *fm;
    fm = fopen("secv3.out","w");


    fscanf(fp,"%d",&N);
    fscanf(fp,"%d",&Lmin);
    fscanf(fp,"%d",&Lmax);

    for(i=1;i<=N;i++)
        fscanf(fp,"%d",&VCost[i]);

    for(i=1;i<=N;i++)
        fscanf(fp,"%d",&VTimp[i]);

    for(i=1;i<=N;i++)
    {
        Cost = 0;
        Timp = 0;

        for(j=Lmin;j<=Lmax;j++)
            for(k=0;k<j;k++)
            {
                Cost = Cost + VCost[i+k];
                Timp = Timp + VTimp[i+k];
                Med = Cost / Timp;
                if(Med > Max)
                    Max = Med;
            }
    }
    //printf("%.2f",Max);
    fprintf(fm,"%.2f",Max);
    fclose(fp);
    fclose(fm);
}