#include<fstream>
#include<iomanip>

using namespace std;

#define max_n 30010

ifstream f("secv3.in");
ofstream g("secv3.out");

int n , l , u;
int V[max_n] , T[max_n];

void read(){
		
	f>>n>>l>>u;
	
	for( int i = 1 ; i <= n ; i++ )
	{
		f>>V[i];
		V[i] += V[i-1];
	}
	
	for( int i = 1 ; i <= n ; i++ ){
		f>>T[i];
		T[i] += T[i-1];	
	}
	
}


int main(){
	
	read();
	
	double fract , maxim = -2;
	
	for( int j , i = 1 ; i <= n ; i++ ){
		for( j = l - 1 ; j < u && (i+j) <= n ; j++ ){
			fract = ((double)V[j+i] - V[i - 1]) / ((double)T[j+i] - T[i-1]);
			if( fract > maxim )
				maxim = fract;
		}
	}
	
	g<<fixed<<setprecision(2)<<maxim<<"\n";
	
	return 0;
}