// >>> TEMPLATES
#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ld = long double;
using i32 = int32_t;
using i64 = int64_t;
using u32 = uint32_t;
using u64 = uint64_t;
#define int ll
#define double ld
#define rep(i,n) for (int i = 0; i < (int)(n); i++)
#define rep1(i,n) for (int i = 1; i <= (int)(n); i++)
#define repR(i,n) for (int i = (int)(n)-1; i >= 0; i--)
#define rep1R(i,n) for (int i = (int)(n); i >= 1; i--)
#define loop(i,a,B) for (int i = a; i B; i++)
#define loopR(i,a,B) for (int i = a; i B; i--)
#define all(x) begin(x), end(x)
#define allR(x) rbegin(x), rend(x)
#define pb push_back
#define eb emplace_back
#define mp make_pair
#define fst first
#define snd second
template <class Int> auto constexpr inf = numeric_limits<Int>::max()/2-1;
auto constexpr INF32 = inf<int32_t>;
auto constexpr INF64 = inf<int64_t>;
auto constexpr INF   = inf<int>;
#ifdef LOCAL
#include "debug.hpp"
#else
#define dump(...) (void)(0)
#define say(x) (void)(0)
#define debug if (0)
#endif
template <class T> using pque_max = priority_queue<T>;
template <class T> using pque_min = priority_queue<T, vector<T>, greater<T> >;
template <class T, class = typename T::iterator, class = typename enable_if<!is_same<T, string>::value>::type>
ostream& operator<<(ostream& os, T const& v) { bool f = true; for (auto const& x : v) os << (f ? "" : " ") << x, f = false; return os; }
template <class T, class = typename T::iterator, class = typename enable_if<!is_same<T, string>::value>::type>
istream& operator>>(istream& is, T &v) { for (auto& x : v) is >> x; return is; }
template <class T, class S> ostream& operator<<(ostream& os, pair<T,S> const& p) { return os << "(" << p.first << ", " << p.second << ")"; }
template <class T, class S> istream& operator>>(istream& is, pair<T,S>& p) { return is >> p.first >> p.second; }
struct IOSetup { IOSetup() { cin.tie(nullptr); ios::sync_with_stdio(false); cout << fixed << setprecision(15); } } iosetup;
template <class F> struct FixPoint : private F {
    constexpr FixPoint(F&& f) : F(forward<F>(f)) {}
    template <class... T> constexpr auto operator()(T&&... x) const { return F::operator()(*this, forward<T>(x)...); }
};
struct MakeFixPoint {
    template <class F> constexpr auto operator|(F&& f) const { return FixPoint<F>(forward<F>(f)); }
};
#define MFP MakeFixPoint()|
#define def(name, ...) auto name = MFP [&](auto &&name, __VA_ARGS__)
template <class T, size_t d> struct vec_impl {
    using type = vector<typename vec_impl<T,d-1>::type>;
    template <class... U> static type make_v(size_t n, U&&... x) { return type(n, vec_impl<T,d-1>::make_v(forward<U>(x)...)); }
};
template <class T> struct vec_impl<T,0> { using type = T; static type make_v(T const& x = {}) { return x; } };
template <class T, size_t d = 1> using vec = typename vec_impl<T,d>::type;
template <class T, size_t d = 1, class... Args> auto make_v(Args&&... args) { return vec_impl<T,d>::make_v(forward<Args>(args)...); }
template <class T> void quit(T const& x) { cout << x << endl; exit(0); }
template <class T, class U> constexpr bool chmin(T& x, U const& y) { if (x > y) { x = y; return true; } return false; }
template <class T, class U> constexpr bool chmax(T& x, U const& y) { if (x < y) { x = y; return true; } return false; }
template <class It> constexpr auto sumof(It b, It e) {
    using S = typename iterator_traits<It>::value_type;
    using T = conditional_t<is_signed_v<S>,i64,u64>;
    return accumulate(b,e,T{});
}
template <class T> int sz(T const& x) { return x.size(); }
template <class C, class T> int lbd(C const& v, T const& x) {
    return lower_bound(v.begin(), v.end(), x)-v.begin();
}
template <class C, class T> int ubd(C const& v, T const& x) {
    return upper_bound(v.begin(), v.end(), x)-v.begin();
}
const int dx[] = { 1,0,-1,0 };
const int dy[] = { 0,1,0,-1 };
constexpr int popcnt(ll x) { return __builtin_popcountll(x); }
template <class Int> Int rand(Int a, Int b) { // [a,b]
    static mt19937_64 mt{random_device{}()};
    return uniform_int_distribution<Int>(a,b)(mt);
}
i64 irand(i64 a, i64 b) { return rand<i64>(a,b); }
u64 urand(u64 a, u64 b) { return rand<u64>(a,b); }
// <<<
// >>> modint
template <uint32_t md>
class modint {
    static_assert(md < (1u<<31), "");
    using M = modint;
    using i64 = int64_t;
    uint32_t x;
public:
    static constexpr uint32_t mod = md;
    constexpr modint(i64 x = 0) : x((x%=md) < 0 ? x+md : x) { }
    constexpr i64 val() const { return x; }
    constexpr explicit operator i64() const { return x; }
    constexpr bool operator==(M r) const { return x == r.x; }
    constexpr bool operator!=(M r) const { return x != r.x; }
    constexpr M operator+() const { return *this; }
    constexpr M operator-() const { return M()-*this; }
    constexpr M& operator+=(M r) { x += r.x; x = (x < md ? x : x-md); return *this; }
    constexpr M& operator-=(M r) { x += md-r.x; x = (x < md ? x : x-md); return *this; }
    constexpr M& operator*=(M r) { x = (uint64_t(x)*r.x)%md; return *this; }
    constexpr M& operator/=(M r) { return *this *= r.inv(); }
    constexpr M operator+(M r) const { return M(*this) += r; }
    constexpr M operator-(M r) const { return M(*this) -= r; }
    constexpr M operator*(M r) const { return M(*this) *= r; }
    constexpr M operator/(M r) const { return M(*this) /= r; }
    friend constexpr M operator+(i64 x, M y) { return M(x)+y; }
    friend constexpr M operator-(i64 x, M y) { return M(x)-y; }
    friend constexpr M operator*(i64 x, M y) { return M(x)*y; }
    friend constexpr M operator/(i64 x, M y) { return M(x)/y; }
    constexpr M inv() const { assert(x > 0); return pow(md-2); }
    constexpr M pow(i64 n) const {
        assert(not (x == 0 && n == 0));
        if (n < 0) return inv().pow(-n);
        M v = *this, r = 1;
        for (; n > 0; n >>= 1, v *= v) if (n&1) r *= v;
        return r;
    }
#ifdef LOCAL
    friend string to_s(M r) { return to_s(r.val(), mod); }
#endif
    friend ostream& operator<<(ostream& os, M r) { return os << r.val(); }
    friend istream& operator>>(istream& is, M &r) { i64 x; is >> x; r = x; return is; }
};
// <<<
constexpr int64_t MOD = 998244353;
using mint = modint<MOD>;
mint sgn(int n) { return n%2 == 0 ? +1 : -1; }
// >>> mod table
template <uint32_t mod>
struct ModTable {
    vector<uint32_t> fact = {1,1}, finv = {1,1}, inv = {0,1};
    void calc(int n) {
        int old = fact.size();
        if (n < old) return;
        fact.resize(n+1);
        finv.resize(n+1);
        inv.resize(n+1);
        for (uint32_t i = old; i <= n; i++) {
            fact[i] = uint64_t(fact[i-1])*i % mod;
            inv[i] = mod - uint64_t(inv[mod%i])*(mod/i) % mod;
            finv[i] = uint64_t(finv[i-1])*inv[i] % mod;
        }
    }
};
ModTable<MOD> mod_tab;

modint<MOD> fact(int n) {
    assert(0 <= n);
    return mod_tab.calc(n), mod_tab.fact[n];
}
modint<MOD> finv(int n) {
    assert(0 <= n);
    return mod_tab.calc(n), mod_tab.finv[n];
}
modint<MOD> C(int n, int k) {
    if (n < 0 || k < 0 || n < k) return 0;
    return fact(n)*finv(k)*finv(n-k);
}
modint<MOD> P(int n, int k) {
    assert(k >= 0); assert(n >= k);
    return fact(n)*finv(n-k);
}
// <<<
// >>> FPS
template <class NTT>
struct FormalPowerSeries : NTT, vector<typename NTT::modint> {
    using mint = typename NTT::modint;
    using NTT::conv;
    using vector<mint>::vector; // inherit constructors
    using FPS = FormalPowerSeries;
    FormalPowerSeries() : vector<mint>() {}
    FormalPowerSeries(vector<mint> const& v) : vector<mint>(v) {}
    FormalPowerSeries(mint const& x) : vector<mint>({x}) {}
    mint get(int i) const {
        assert(i >= 0);
        if (i < (int)this->size()) return (*this)[i];
        else return 0;
    }
    bool operator==(FPS const& r) const {
        const int n = min(this->size(), r.size());
        rep (i,n) {
            if ((*this)[i] != r[i]) return false;
        }
        for (int i = n; i < (int)this->size(); ++i) {
            if ((*this)[i] != mint(0)) return false;
        }
        for (int i = n; i < (int)r.size(); ++i) {
            if (r[i] != mint(0)) return false;
        }
        return true;
    }
    bool operator!=(FPS const& r) const { return !((*this) == r); }
    FPS operator+(FPS const& r) const { return FPS(*this) += r; }
    FPS operator-(FPS const& r) const { return FPS(*this) -= r; }
    FPS& operator+=(FPS const& r) {
        if (r.size() > this->size()) this->resize(r.size());
        rep (i,r.size()) (*this)[i] += r[i];
        return *this;
    }
    FPS& operator-=(FPS const& r) {
        if (r.size() > this->size()) this->resize(r.size());
        rep (i,r.size()) (*this)[i] -= r[i];
        return *this;
    }
    FPS operator*(FPS const& r) const {
        if (this->empty() || r.empty()) return {};
        return conv(*this,r);
    }
    FPS& operator*=(FPS const& r) { return *this = *this * r; }
    friend FPS operator+(mint const& x, FPS const& f) { return FPS{x}+f; }
    friend FPS operator-(mint const& x, FPS const& f) { return FPS{x}-f; }
    friend FPS operator*(mint const& x, FPS const& f) { return FPS{x}*f; }
    friend FPS operator+(FPS const& f, mint const& x) { return f+FPS{x}; }
    friend FPS operator-(FPS const& f, mint const& x) { return f-FPS{x}; }
    friend FPS operator*(FPS const& f, mint const& x) { return f*FPS{x}; }
    FPS take(int sz) const {
        FPS ret(this->begin(), this->begin() + min<int>(this->size(),sz));
        ret.resize(sz);
        return ret;
    }
    FPS inv(int sz = -1) const {
        assert(this->size()); assert((*this)[0] != mint(0));
        if (sz < 0) sz = this->size();
        FPS ret = { mint(1)/(*this)[0] };
        for (int i = 1; i < sz; i <<= 1) {
            ret = ret + ret - ret*ret*take(i<<1);
            ret.resize(i<<1);
        }
        ret.resize(sz);
        return ret;
    }
    FPS diff() const {
        FPS ret(max<int>(0,this->size()-1));
        rep (i,ret.size()) ret[i] = (*this)[i+1]*mint(i+1);
        return ret;
    }
    FPS integral() const {
        FPS ret(this->size()+1);
        ret[0] = 0;
        rep (i,this->size()) ret[i+1] = (*this)[i]/mint(i+1);
        return ret;
    }
    FPS log(int sz = -1) const {
        assert(this->size()); assert((*this)[0] == mint(1));
        if (sz < 0) sz = this->size();
        return (diff()*inv(sz)).take(sz-1).integral();
    }
    // FPS log(int sz = -1) const {
    //     assert(this->size()); assert((*this)[0] == mint(1));
    //     if (sz < 0) sz = this->size();
    //     auto ret = diff()*inv(sz);
    //     ret.resize(sz);
    //     for (int i = sz-1; i > 0; --i) ret[i] = ret[i-1]/mint(i);
    //     ret[0] = 0;
    //     return ret;
    // }
    FPS exp(int sz = -1) const {
        FPS ret = {mint(1)};
        if (this->empty()) return ret;
        assert((*this)[0] == mint(0));
        if (sz < 0) sz = this->size();
        for (int i = 1; i < sz; i <<= 1) {
            ret *= take(i<<1) + mint(1) - ret.log(i<<1);
            ret.resize(i<<1);
        }
        ret.resize(sz);
        return ret;
    }
    FPS pow(int64_t k, int sz = -1) const {
        if (sz < 0) sz = this->size();
        int deg = 0;
        while (deg < sz && (*this).get(deg) == mint(0)) ++deg;
        assert(k >= 0 || deg == 0);

        auto c = mint(1)/(*this).get(deg);
        FPS ret(sz-deg);
        rep (i,sz-deg) ret[i] = (*this).get(deg+i)*c;
        ret = (ret.log()*k).exp() * (*this).get(deg).pow(k);

        ret.resize(sz);
        for (int i = sz-1; i >= 0; --i) {
            int j = i-deg*k;
            ret[i] = (j >= 0 ? ret[j] : mint(0));
        }
        return ret;
    }
    mint eval(mint x) const;
};
// <<<
// >>> NTT
template <class ModInt, int64_t g>
struct NTT {
    using modint = ModInt;
    static constexpr int64_t mod = ModInt::mod, gen = g, max_lg = __builtin_ctzll(mod-1);
    // mod:prime, g:primitive root
    static_assert(mod > 0 && g > 0 && max_lg > 0, "");

    using arr_t = array<ModInt,max_lg+1>;
    static arr_t ws,iws;
    static void init() {
        static bool built = false;
        if (built) return;
        for (int i = 0; i <= max_lg; i++) {
            ws[i] = -ModInt(g).pow((mod-1)>>(i+2));
            iws[i] = ModInt(1)/ws[i];
        }
        built = true;
    }
    static void ntt(ModInt a[], int lg) {
        for (int b = lg-1; b >= 0; b--) {
            ModInt w = 1;
            for (int i = 0, k = 0; i < (1<<lg); i += 1<<(b+1)) {
                for (int j = i; j < (i|(1<<b)); j++) {
                    const int k = j|(1<<b);
                    const auto x = a[j], y = a[k];
                    a[j] = x + y*w;
                    a[k] = x - y*w;
                }
                w *= ws[__builtin_ctz(++k)];
            }
        }
//        bit_reverse(a,1<<lg);
    }
    static void intt(ModInt a[], int lg) {
//        bit_reverse(a,1<<lg);
        for (int b = 0; b < lg; b++) {
            ModInt w = 1;
            for (int i = 0, k = 0; i < (1<<lg); i += 1<<(b+1)) {
                for (int j = i; j < (i|(1<<b)); j++) {
                    const int k = j|(1<<b);
                    const auto x = a[j], y = a[k];
                    a[j] = x + y;
                    a[k] = w*(x - y);
                }
                w *= iws[__builtin_ctz(++k)];
            }
        }
    }
    template <class T>
    static vector<ModInt> conv(vector<T> const& a, vector<T> const& b) {
        if (a.empty() || b.empty()) return {};
        init();
        const int s = a.size() + b.size() - 1, lg = __lg(2*s-1);
        assert(lg <= max_lg);

        vector<ModInt> aa(1<<lg);
        rep (i,a.size()) aa[i] = (int64_t)a[i];
        ntt(aa.data(), lg);

        vector<ModInt> bb(1<<lg);
        rep (i,b.size()) bb[i] = (int64_t)b[i];
        ntt(bb.data(), lg);

        const auto x = ModInt(1)/ModInt(1<<lg);
        rep (i,1<<lg) aa[i] *= bb[i]*x;
        intt(aa.data(), lg); aa.resize(s);
        return aa;
    }
    template <class T>
    static vector<ModInt> conv(vector<T> const& a) {
        if (a.empty()) return {};
        init();
        const int s = a.size()*2 - 1, lg = __lg(2*s-1);
        assert(lg <= max_lg);

        vector<ModInt> aa(1<<lg);
        rep (i,a.size()) aa[i] = (int64_t)a[i];
        ntt(aa.data(), lg);

        const auto x = ModInt(1)/ModInt(1<<lg);
        rep (i,1<<lg) aa[i] *= aa[i]*x;
        intt(aa.data(), lg); aa.resize(s);
        return aa;
    }
};
template <class ModInt, int64_t g>
typename NTT<ModInt,g>::arr_t NTT<ModInt,g>::ws;
template <class ModInt, int64_t g>
typename NTT<ModInt,g>::arr_t NTT<ModInt,g>::iws;
// <<<
using ntt = NTT<mint,3>;
using FPS = FormalPowerSeries<ntt>;

int32_t main() {
    int n; cin >> n;
    vector<int> h(2*n); cin >> h;

    map<int,int> cnt;
    for (int x : h) cnt[x]++;

    queue<FPS> q;
    for (auto [_,m] : cnt) {
        FPS f(m/2+1);
        rep (i,f.size()) f[i] = C(m,2*i)*fact(2*i)/mint(2).pow(i)*finv(i)*sgn(i);
        q.push(f);
        dump(m,f);
    }
    {
        FPS f(n+1);
        rep (i,f.size()) f[i] = fact(2*i)/mint(2).pow(i)*finv(i);
        q.push(f);
        dump(f);
    }

    while (sz(q) > 1) {
        auto f = q.front(); q.pop();
        auto g = q.front(); q.pop();
        q.push(f*g);
    }

    auto f = q.front();
    dump(f);

    cout << f[n] << endl;


}


Measured memory_bytes: 17684