# include <iostream>
# include <algorithm>
# include <vector>
# include <string>
# include <set>
# include <map>
# include <cmath>
# include <iomanip>
# include <functional>
# include <utility>
# include <stack>
# include <queue>
# include <list>
# include <tuple>
# include <unordered_map>
# include <numeric>
# include <complex>
# include <bitset>
using namespace std;
using LL = long long;
using ULL = unsigned long long;
constexpr int INF = 2000000000;
constexpr int HINF = INF / 2;
constexpr double DINF = 100000000000000000.0;
constexpr long long LINF = 9223372036854775807;
constexpr long long HLINF = 4500000000000000000;
constexpr long long MMOD = 500000004;
const double PI = acos(-1);
int dx[4] = { 0,1,0,-1 }, dy[4] = { 1,0,-1,0 };
# define ALL(x) (x).begin(),(x).end()
# define UNIQ(c) (c).erase(unique(ALL((c))), end((c)))
# define mp make_pair
# define eb emplace_back
# define FOR(i,a,b) for(int i=(a);i<(b);++i)
# define REP(i,n) FOR(i,0,n)
# define INIT std::ios::sync_with_stdio(false);std::cin.tie(0);
int a[101010], b[101010];
vector<pair<int, int>>v;
const int MOD = 1e9 + 7;
int main(){
int n;
cin >> n;
for (int i = 0; i < n; i++) cin >> a[i], v.emplace_back(a[i], 1);
for (int i = 0; i < n; i++) cin >> b[i], v.emplace_back(b[i], 2);
sort(ALL(v));
LL ans = 1;
int pa = 0, pb = 0;
for (int i = 0; i < 2 * n; i++) {
if (v[i].second == 1) {
if (pb == 0)pa++;
else (ans *= pb) %= MOD,pb--;
}
if (v[i].second == 2) {
if (pa == 0)pb++;
else (ans *= pa) %= MOD,pa--;
}
}
cout << ans%MOD << endl;
}