codeforces 780B

#include<stdio.h>
#include<algorithm>
#include<cstring>
#include<string>
#include<cmath>

using namespace std;

#define MAXN 60010
#define inf  1000000000.0
double ind[MAXN],v[MAXN];
int n;

double f(double a)
{
    double t1=0;
    for(int i=1;i<=n;i++)
    {
        double d=fabs(a-ind[i]);
        double t=d/v[i];
        t1=max(t1,t);
    }
    return t1;

}
int main()
{

    scanf("%d",&n);
    for(int i=1;i<=n;i++)
        scanf("%lf",&ind[i]);
    for(int i=1;i<=n;i++)
        scanf("%lf",&v[i]);
    double l,r;
    l=-inf;
    r=inf;
    for(int i=1;i<=500;i++)
    {
        double ll=l+(r-l)/3;
        double rr=l+2*(r-l)/3;
        //printf("%lf %lf",l,r);
        if(f(rr)-f(ll)>1e-7)
            r=rr;
        else
            l=ll;
    }
    printf("%.12lf\n",f(l));
    return 0;
}