#include<fstream.h>
#define dim 30001
int v[2][dim];
int main()
{ifstream f("secv3.in");
 ofstream g("secv3.out");
 int n,i,l,u,j;
 f>>n>>l>>u;
 for(i=1;i<=n;i++)
  {f>>v[0][i];
   v[0][i]+=v[0][i-1];
  }
 for(i=1;i<=n;i++)
  v[0][i]=v[0][i]*100;
 for(i=1;i<=n;i++)
  {f>>v[1][i];
   v[1][i]+=v[1][i-1];
  }
 int n1,n2,max=0,man1,man2;
 for(i=1;i<=n;i++)
  {n1=(i+l)-1;
   n2=(i+u)-1;
   for(j=n1;j<=n2;j++)
    {man1=v[0][j]-v[0][i-1];
     man2=v[1][j]-v[1][i-1];
     if(man2)
      if((man1/man2)>max) max=man1/man2;
    }
  }
 f.close();
 float rez;
 rez=max/100.0;
 g<<rez<<'\n';
 g.close();
return 0;
}