#include <algorithm>
#include <cstdio>
#include <vector>
#define repeat(i, n) for (int i = 0; (i) < int(n); ++(i))
#define whole(x) begin(x), end(x)
using ll = long long;
using namespace std;

constexpr int mod = 1e9+7;
int main() {
    // input
    int n; scanf("%d", &n);
    vector<int> a(n); repeat (i, n) scanf("%d", &a[i]);
    vector<int> b(n); repeat (i, n) scanf("%d", &b[i]);
    // solve
    vector<pair<int, bool> > events;
    repeat (i, n) {
        events.emplace_back(a[i], false);
        events.emplace_back(b[i], true);
    }
    sort(whole(events));
    ll result = 1;
    int cnt = 0;
    for (auto event : events) {
        int delta = (event.second ? 1 : -1);
        if (cnt != 0 and (cnt > 0) != event.second) {
            result = (result * std::abs(cnt)) % mod;
        }
        cnt += delta;
    }
    // output
    printf("%lld\n", result);
    return 0;
}
