#include <cstdio>
#include <algorithm>

using namespace std;

int cost[30010],timp[30010];

int main()
{
    freopen("secv3.in","r",stdin);
    freopen("secv3.out","w",stdout);
    int n,l,u;
    float st,dr,mid,maxx,a;
    scanf("%d%d%d",&n,&l,&u);
    for(int i=1;i<=n;i++)
        scanf("%d",&cost[i]);
    for(int i=1;i<=n;i++)
        scanf("%d",&timp[i]);
    st=0,dr=1000;
    for(int i=1;i<=100;i++)
    {
        mid=(st+dr)/2;
        maxx=-1;
        a=0;
        for(int j=1;j<=n;j++)
            if(a>=0) {a=a+cost[j]-timp[j]*mid;maxx=max(maxx,a);}
            else {a=cost[j]-timp[j]*mid;maxx=max(maxx,a);}
        if(maxx>=0) st=mid;
        else dr=mid;
    }
    printf("%.2f",dr);
    return 0;
}