package main

import . "fmt"
import . "slices"

func main() {
	var n int
	Scan(&n)
	a:=make([]int,n)
	b:=make([]int,n)
	for i:=range a {
		Scan(&a[i])
	}
	for i:=range b {
		Scan(&b[i])
	}
	Sort(a)
	dp:=make([][]int,n+1)
	for i:=range dp {
		dp[i]=make([]int,1<<n)
	}
	dp[0][0]=1
	for i,v:=range a {
		for j,w:=range dp[i] {
			if w==0 {
				continue
			}
			for k,u:=range b {
				p:=j&(1<<k)
				if p!=0 {
					continue
				}
				if v<=u {
					continue
				}
				dp[i+1][j|p]+=w
			}
		}
	}
	xs:=dp[n]
	Reverse(xs)
	for _,v:=range xs {
		if v>0 {
			Println(v)
			return
		}
	}
}