#include <iostream>
#include <algorithm>
#include <iomanip>
#include <vector>
#include <queue>
#include <set>
#include <map>
#define N_MAX 200002

#define debug_value(x) cerr << "line" << __LINE__ << ":<" << __func__ << ">:" << #x << "=" << x << endl;
#define debug(x) cerr << "line" << __LINE__ << ":<" << __func__ << ">:" << x << endl;

using namespace std;
typedef long long ll;

const ll MOD = 998244353;

#define root 3
    
unsigned int add(const unsigned int x, const unsigned int y){
    return (x + y < MOD) ? x + y : x + y - MOD;
}
    
unsigned int sub(const unsigned int x, const unsigned int y){
    return (x >= y) ? (x - y) : (MOD - y + x);
}
    
unsigned int mul(const unsigned int x, const unsigned int y){
    return (unsigned long long)x * y % MOD;
}
    
unsigned int mod_pow(unsigned int x, unsigned int n){
    unsigned int res = 1;
    while(n > 0){
        if(n & 1){ res = mul(res, x); }
        x = mul(x, x);
        n >>= 1;
    }
    return res;
}
    
unsigned int inverse(const unsigned int x){
    return mod_pow(x, MOD - 2);
}
    
void ntt(vector<int>& a, const bool rev = false){
    unsigned int i, j, k, l, p, q, r, s;
    const unsigned int size = a.size();
    if(size == 1) return;
    vector<int> b(size);
    r = rev ? (MOD - 1 - (MOD - 1) / size) : (MOD - 1) / size;
    s = mod_pow(root, r);
    vector<unsigned int> kp(size / 2 + 1, 1);
    for(i = 0; i < size / 2; ++i) kp[i + 1] = mul(kp[i], s);
    for(i = 1, l = size / 2; i < size; i <<= 1, l >>= 1){
        for(j = 0, r = 0; j < l; ++j, r += i){
            for(k = 0, s = kp[i * j]; k < i; ++k){
                p = a[k + r], q = a[k + r + size / 2];
                b[k + 2 * r] = add(p, q);
                b[k + 2 * r + i] = mul(sub(p, q), s);
            }
        }
        swap(a, b);
    }
    if(rev){
        s = inverse(size);
        for(i = 0; i < size; i++){ a[i] = mul(a[i], s); }
    }
}
    
vector<int> convolute(const vector<int>& a, const vector<int>& b){
    const int size = (int)a.size() + (int)b.size() - 1;
    int t = 1;
    while(t < size){ t <<= 1; }
    vector<int> A(t, 0), B(t, 0);
    for(int i = 0; i < (int)a.size(); i++){ A[i] = a[i]; }
    for(int i = 0; i < (int)b.size(); i++){ B[i] = b[i]; }
    ntt(A), ntt(B);
    for (int i = 0; i < t; i++){ A[i] = mul(A[i], B[i]); }
    ntt(A, true);
    A.resize(size);
    return A;
}

class ModInt{
    public:
    ll v;
    ModInt(ll _v = 0){
        v = _v;
    }
    ModInt operator+(ll n){
        return ModInt((v+n)%MOD);
    }
    ModInt operator-(ll n){
        return ModInt((v-n+MOD)%MOD);
    }
    ModInt operator*(ll n){
        return ModInt((v*n)%MOD);
    }
    ModInt operator/(ll n){
        return ModInt((ModInt(n).inv()*v).v%MOD);
    }

    void operator+=(ll n){
        v = (v+n)%MOD;
    }
    void operator-=(ll n){
        v = (v-n+MOD)%MOD;
    }
    void operator*=(ll n){
        v = (v*n)%MOD;
    }
    
    
    ModInt operator+(ModInt n){
        return ModInt((v+n.v)%MOD);
    }
    ModInt operator-(ModInt n){
        return ModInt((v-n.v+MOD)%MOD);
    }
    ModInt operator*(ModInt n){
        return ModInt((v*n.v)%MOD);
    }
    ModInt operator/(ModInt n){
        return ModInt((n.inv()*v).v%MOD);
    }

    void operator+=(ModInt n){
        v = (v+n.v)%MOD;
    }
    void operator-=(ModInt n){
        v = (v-n.v+MOD)%MOD;
    }
    void operator*=(ModInt n){
        v = (v*n.v)%MOD;
    }

    void operator=(ModInt n){
        v = n.v;
    }
    void operator=(ll n){
        v = n;
    }

    ModInt inv(){
        if(v == 1) return ModInt(1);
        else return ModInt(MOD-ModInt(MOD%v).inv().v*(MOD/v)%MOD);
    }
};

ostream& operator<<(ostream& os, const ModInt& m){
    os << m.v;
    return os;
}

istream & operator >> (istream &in,  ModInt &m){
    in >> m.v;
    return in;
}

ModInt pow(ModInt a, ll n) {
	ModInt ans = 1;
	ModInt tmp = a;
	for (int i = 0; i <= 60; i++) {
		ll m = (ll)1 << i;
		if (m & n) {
		ans *= tmp;
		}
		tmp *= tmp;
	}
	return ans;
}

ModInt inv[N_MAX],fac[N_MAX],finv[N_MAX];

void init(){
    fac[0]=1;fac[1]=1;
    finv[0]=1;finv[1]=1;
    inv[1]=1;
    for(int i=2;i<N_MAX;i++){
        inv[i]=(ModInt)MOD-inv[MOD%i]*(MOD/i);
        fac[i]=fac[i-1]*(ll) i;
        finv[i]=finv[i-1]*inv[i];
    }
}

ModInt comb(ll n, ll r){
  if(n < r){
      return ModInt(0);
  }else{
      return fac[n]*finv[r]*finv[n-r];
  }
}

int N;
int cnt[100005];

vector<int> calc(vector<vector<int>> v){
    if(v.size() == 1) return v[0];
    if(v.size() == 2) return convolute(v[0], v[1]);
    int sz = v.size();
    vector<vector<int>> l, r;
    int tmp_sum = 0;
    for(int i = 0; i < sz; i++){
        if(i*2 > sz) r.push_back(v[i]);
        else l.push_back(v[i]);
    }
    return convolute(calc(l), calc(r));
}

// n人をm組
ModInt devide(ll n, ll m){
    return comb(n, 2*m)*fac[2*m]*finv[m]/pow(2, m);
}

int main(){
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout << setprecision(10) << fixed;
    cin >> N;
    for(int i = 0; i < 2*N; i++){
        int h; cin >> h; cnt[h]++;
    }
    init();
    vector<vector<int>>v;

    for(int i = 1; i <= 100000; i++){
        if(cnt[i] == 0) continue;
        vector<int> u;
        for(int j = 0; 2*j <= cnt[i]; j++){
            ModInt tmp = devide(cnt[i], j);
            u.push_back(tmp.v);
        }
        v.push_back(u);
    }
    ModInt ans = 0;
    auto u = calc(v);
    
    for(int i = 0; 2*i <= 2*N && i < u.size(); i++){
        ModInt tmp = ModInt(u[i])*devide(2*N-2*i, N-i);
        if(i%2 == 0){
            ans += tmp;
        }else{
            ans -= tmp;
        }
        // cout << u[i] << ':' << tmp << ' ';
    }
    // cout << endl;
    // cout << devide(4, 2) << endl;
    cout << ans << endl;
}

Measured memory_bytes: 41116