import std.stdio, std.string, std.conv;
import std.range, std.algorithm, std.array, std.typecons;
import std.math, std.numeric;

alias Pair = Tuple!(int, "x", int, "c");
enum mod = 10^^9 + 7;

void main() {
    int n; scan(n);
    auto a = iota(n).map!(i => Pair(readln.chomp.to!int, 0)).array;
    auto b = iota(n).map!(i => Pair(readln.chomp.to!int, 1)).array;
    auto ab = (a ~ b).sort!"a.x < b.x"();

    long ans = 1;
    long cnt;
    int  col;

    foreach (abi ; ab) {
        if (cnt == 0) {
            col = abi.c;
        }

        if (abi.c == col) {
            cnt++;
        }
        else {
            ans *= cnt;
            ans %= mod;
            cnt--;
        }
    }

    writeln(ans);
}






void scan(T...)(ref T args) {
    import std.stdio : readln;
    import std.algorithm : splitter;
    import std.conv : to;
    import std.range.primitives;

    auto line = readln().splitter();
    foreach (ref arg; args) {
        arg = line.front.to!(typeof(arg));
        line.popFront();
    }
    assert(line.empty);
}



void fillAll(R, T)(ref R arr, T value) {
    static if (is(typeof(arr[] = value))) {
        arr[] = value;
    }
    else {
        foreach (ref e; arr) {
            fillAll(e, value);
        }
    }
}
