#include<bits/stdc++.h>
#define int long long
#define DEBUG(x) cerr<<#x<<'='<<x<<endl
using namespace std;
int a[100005],b[100005];
bool cmp(int a,int b)
{
	return a<b;
}
int ans[100005];
const int mod=1e9+7; 
signed main()
{
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    //freopen(".in","r",stdin);
    //freopen(".out","w",stdout);
    int n;
    cin>>n;
    for(int i=1;i<=n;i++)
    {
    	cin>>a[i];
	}
	for(int i=1;i<=n;i++)
	{
		cin>>b[i];
	}
	sort(a+1,a+1+n,cmp);
	sort(b+1,b+1+n,cmp);
	int i=1,j=1;
	for(i=1;i<=n;i++)
	{
		while(b[i]>=a[j]&&j<=n)
		{
			ans[i]=j;
			j++;
		}
		j--;
	}
	for(i=j+1;i<=n;i++)
	{
		ans[i]=n;
	}
	int ans1=1;
	for(i=1;i<=n;i++)
	{
		if(i!=1)
		{
			ans1*=ans[i]-i+1;
			ans1%=mod;
		}
		else
		{
			ans1*=ans[i];
			ans1%=mod;
		}
	}
	cout<<ans1%mod;
    //fclose(stdin);
    //fclose(stdout);
	return 0;
}
/*1 2 3 4
  2 2 4 4*/