#include #include #include #include #include #include #include #include #include using namespace std; #define rep(i,n) for (int i = 0; i < (n); i++) #define vi vector #define vll vector #define vb vector #define vs vector #define all(x) x.begin() , x.end() #define pb push_back #define eb emplace_back #define chmax(x,y) (x) = max((x) , (y)) #define chmin(x,y) (x) = min((x) , (y)) #define fi first #define se second typedef long long ll; typedef long double ld; //const int MOD = int(1e9) + 7; //const int MOD = 998244353; const ll MOD = ll(1e9) + 7; //const ll MOD = 998244353; const ld PI = 3.1415926535897932384626; const int INF = 1001001001; const ll LINF = 1001001001001001001; const int MX = 220000; ll gcd (ll a , ll b) { if (a < b) swap(a , b); if (a % b == 0) return b; else return gcd(b , a % b); } ll lcm (ll a , ll b) { return a / gcd(a , b) * b; } ll lin() { ll x; scanf("%lld" , &x); return x; } int in() { int x; scanf("%d" , &x); return x; } bool is_palindrome (string s) { string t = s; reverse(all(t)); return (s == t); } void io_setup() { cout << fixed << setprecision(30); } ll modpow (ll x , ll p) { ll ret = 1; while (p) { if (p % 2 == 1) { ret *= x; ret %= MOD; } x *= x; x %= MOD; p /= 2; } return ret; } ll moddiv (ll a , ll b) { return a * modpow(b , MOD - 2) % MOD; } ll modsub (ll a , ll b) { if (a >= b) return (a - b) % MOD; else return (MOD - a + b); } vll fact(MX); vll factinv(MX); void init_fact () { fact[0] = 1; for (int i = 1; i < MX; i++) { fact[i] = 1LL * i * fact[i - 1] % MOD; } for (int i = 0; i < MX; i++) { factinv[i] = modpow(fact[i] , MOD - 2); } } ll nCk (ll n , ll k) { return ((fact[n] * factinv[k] % MOD) * factinv[n - k] % MOD); } bool is_prime (int x) { if (x == 2 || x == 3 || x == 5 || x == 7) { return true; } for (ll i = 2; i*i <= x; i++) { if (x % i == 0) { return false; } } return true; } vb prime_table(MX , true); void init_prime() { for (int i = 2; i < MX; i++) { for (int j = i + i; j < MX; j += i) { prime_table[j] = false; } } return; } void solve () { int n = in(); vi a(n) , b(n); rep(i,n) a[i] = in(); rep(i,n) b[i] = in(); sort(all(a)); sort(all(b)); int cnt_1 = 0 , cnt_2 = 0; do { cnt_1 += 1; int cnt = 0; rep(i,n) cnt += (a[i] > b[i]); if (cnt > n - cnt) cnt_2 += 1; } while (next_permutation(all(b))); //cout << cnt_2 << " " << cnt_1 << endl; ld ans = (ld)cnt_2 / (ld)cnt_1; cout << ans << endl; return; } int main() { io_setup(); //init_fact(); //init_prime(); solve(); return 0; }