#include <bits/stdc++.h>
using namespace std;

using ll = long long;
#define FOR(i, m, n) for (int i = (m); i < (n); i++)
#define REP(i, n) FOR(i, 0, n)
#define REP1(i, n) FOR(i, 1, (n) + 1)
#define ALL(c) (c).begin(), (c).end()
template<class T> inline bool chmin(T& a, T b) {if (a > b) {a = b; return true;} return false;}
template<class T> inline bool chmax(T& a, T b) {if (a < b) {a = b; return true;} return false;}
const int MOD = 1000000007;

int main() {
    int n;
    cin >> n;
    set<pair<int, int>> s;
    int a;
    REP(i, n) {
        cin >> a;
        s.emplace(a, 1);
    }
    int b;
    REP(i, n) {
        cin >> b;
        s.emplace(b, -1);
    }

    ll ans = 1;
    ll c = 0;
    bool st = false;
    int d;
    for (auto p : s) {
        if (!st) {
            st = true;
            d = p.second;
            c++;
        } else {
            if (p.second == d) {
                c++;
            } else {
                ans = ans * c % MOD;
                c--;
            }
            if (c == 0) {
                st = false;
            }
        }
    }

    cout << ans << endl;
}