using System; using System.Collections; using System.Collections.Generic; class TEST{ static void Main(){ Sol mySol =new Sol(); mySol.Solve(); } } class Sol{ public void Solve(){ int[] C=new int[N]; for(int i=0;i<N;i++)C[i]=i; List<int[]> L=new List<int[]>(); do{ L.Add((int[])C.Clone()); }while(NextPermutaion(C)); int cnt=0;int wina=0; for(int i=0;i<L.Count;i++){ for(int j=0;j<L.Count;j++){ cnt++; int a=0;int b=0; for(int k=0;k<N;k++){ if(A[L[i][k]]>B[L[j][k]])a++; if(A[L[i][k]]<B[L[j][k]])b++; } if(a>b)wina++; } } Console.WriteLine("{0}",(double)wina/(double)cnt); } int N; int[] A; int[] B; public Sol(){ N=ri(); A=ria(); B=ria(); } static public bool NextPermutaion<T>(T[] A)where T:IComparable<T>{ for(int i=A.Length-2;i>=0;i--){ if(A[i].CompareTo(A[i+1])<0){ int trgt=Array.FindLastIndex(A,x=>A[i].CompareTo(x)<0); Swap(ref A[i],ref A[trgt]); Array.Reverse(A,i+1,A.Length-(i+1)); return true; } } Array.Reverse(A); return false; } static void Swap<T>(ref T x, ref T y){ T t=x;x=y;y=t; } static String rs(){return Console.ReadLine();} static int ri(){return int.Parse(Console.ReadLine());} static long rl(){return long.Parse(Console.ReadLine());} static double rd(){return double.Parse(Console.ReadLine());} static String[] rsa(){return Console.ReadLine().Split(' ');} static int[] ria(){return Array.ConvertAll(Console.ReadLine().Split(' '),e=>int.Parse(e));} static long[] rla(){return Array.ConvertAll(Console.ReadLine().Split(' '),e=>long.Parse(e));} static double[] rda(){return Array.ConvertAll(Console.ReadLine().Split(' '),e=>double.Parse(e));} }