#include <cstdio>

#include <cstring>

#include <iostream>

#include <algorithm>

using namespace std;

#define eps 1e-7

#define INF 1e18

#define maxn 60005

int n;

double xi[maxn],sp[maxn];

bool check(double ti)

{

    double l=-INF,r=INF;

    for(int i=;i<=n;i++)

    {

        l=max(l,xi[i]-sp[i]*ti);

        r=min(r,xi[i]+sp[i]*ti);

    }

    if(l<=r) return true;

    else return false;

}

int main()

{

    scanf("%d",&n);

    for(int i=;i<=n;i++) scanf("%lf",&xi[i]);

    for(int i=;i<=n;i++) scanf("%lf",&sp[i]);

    double l=,r=1e9,ans;

    while(l<=r)

    {

        double mid=(l+r)/2.0;

        if(check(mid)) r=mid-eps,ans=mid;

        else l=mid+eps;

    }

    printf("%.7lf",ans);

    return ;

}