static void Main(String[] args) {
        System.Console.ReadLine();
        var xs = System.Console.ReadLine();
        var ys = System.Console.ReadLine();
        System.Console.WriteLine(
            SpearmanRank(ToArr(xs), ToArr(ys)).ToString("f3")
        );
    }

    static double[] ToArr(string xs)
    {
        var zs = xs.Trim().Split(' ');
        int l = zs.Length;
        var arr = new double[l];
        int i = -1;
        while(++i<l){
            arr[i] = double.Parse(zs[i]);
        }
        return arr;
    }

    static double SpearmanRank(double[] xs, double[] ys)
    {
        var rxs = GetRank(xs);
        var rys = GetRank(ys);
        
        int n = xs.Length;
        double r = 0;
        for(int i=0;i<n;i++)
        {
            r += Math.Pow(rxs[i] - rys[i], 2);
        }
        
        return 1.0 - (6 * r) / (n * ( Math.Pow(n, 2) - 1 ));
    }

    static double[] GetRank(double[] xs)
    {
        int n = xs.Length;
        var dic = new SortedDictionary<double, List<int>>();
        for(int i=0;i<n;i++)
        {
            var x = xs[i];
            List<int> ps;
            if (!dic.TryGetValue(x, out ps))
            {
                ps = new List<int>();
                dic.Add(x, ps);
            }
            ps.Add(i);
        }
        var rnks = new double[n];
        int p = 1;
        foreach(var d in dic)
        {
            var ws = d.Value;
            foreach(var w in ws)
            {
                rnks[w] = p;
            }
            p++;
        }
        return rnks;
    }