#include<fstream.h>
//#include<iomanip.h>
#define dim 50001
unsigned long n,mn,mx;
int v[dim],w[dim],r,rx;
float rasp;
ifstream f("secv3.in");
void cit()
{unsigned long i;
f>>n>>mn>>mx;
for(i=1;i<=n;i++)
 {f>>v[i];
  v[i]+=v[i-1];
 }
for(i=1;i<=n;i++)
 {f>>w[i];
  w[i]+=w[i-1];
 }
for(i=1;i<=n;i++)v[i]*=100;
}

void caut()
{unsigned long i,j=0,k=0;
//int x,y;
while(j<n)
{for(i=mn;i<=mx;i++)
 {k=j+i;
  if(k<=n)
   {r=(v[k]-v[j])/(w[k]-w[j]);
    //x=v[k]-v[j];y=w[k]-w[j];
    //r=x/y;
    if(r>rx)
     rx=r;
   }
   else break;
  }
 j++;
}
}

int main()
{
cit();
f.close();
caut();
rasp=rx/100.0;
ofstream g("secv3.out");
//g<<(setprecision(2))<<rx<<'\n';
g<<rasp<<'\n';
g.close();
return 0;
}