#include <cstdio>

#define DIM 1666013
#define Nmax 50005
#define INF 0x3f3f3f3f

using namespace std;
char buff[DIM];
int poz = DIM - 1;

int scan(int &A)
{
    A = 0;
    int sign = 1;
    while(('0' > buff[poz] || buff[poz] > '9') && buff[poz] != '-')
        if(++ poz == DIM)
            fread(buff,1,DIM,stdin),poz = 0;
    while(('0' <= buff[poz] && buff[poz] <= '9' ) || buff[poz] == '-')
    {
        if(buff[poz] == '-') sign *= -1;
        else A = A * 10 + buff[poz] - 48;
        if(++poz == DIM)
            fread(buff,1,DIM,stdin),poz = 0;
    }
    A *= sign;
}
int C[Nmax],T[Nmax],I,S,N;

void read()
{
    scan(N),scan(I),scan(S);
    for(int i = 1; i <= N; ++i)
        scan(C[i]);
    for(int i = 1; i <= N; ++i)
        scan(T[i]);
}

void solve()
{
    double best = -999999999;
    for(int i = 1; i <= N ; ++i)
        for(int lung = I; lung <= S; ++lung)
        {
            int t = 0,c = 0;
            for(int j = i; j <= i + lung - 1 && j <= N; ++j)
            {
                t += T[j];
                c += C[j];
            }
            if( best < c/(t*1.0) )
                best = c/(t*1.0);
        }
    printf("%.5lf\n",best);
}

int main()
{
    freopen("secv3.in","r",stdin);
    freopen("secv3.out","w",stdout);

    read();
    solve();

    return 0;
}