#include <cstdio>
#define MAX_N 30100

int A[MAX_N], B[MAX_N];
int i, n, L, U, j, k;
double mx;

int main() {
	freopen("secv3.in", "r", stdin);
	scanf("%d %d %d", &n, &L, &U);
	for ( i=1; i<=n; ++i ) 
		scanf("%d", A+i);
	for ( i=1; i<=n; ++i )
		scanf("%d", B+i);

	for ( i=1; i<=n; ++i ) 
		for ( j=i+L-1; j-i+1 <= U && j<=n; ++j ) {
			double nra=0, nrb=0;
			for ( k=i; k<=j; ++k ) 
				nra += A[k], nrb+=B[k];
			if ( nra/nrb > mx ) mx = nra/nrb;
		}

	fprintf(fopen("secv3.out", "w"), "%.2lf\n", mx);
	return 0;
}