#include <bits/stdc++.h>
using namespace std;
#define int              long long int
#define double           long double
#define print(a)         for(auto x : a) cout << x << " "; cout << endl


const int M = 1000000007;
const int N = 3e5+9;
const int INF = 2e9+1;
const int LINF = 2000000000000000001;



inline int power(int a, int b, int mod) {
    int x = 1;
    a %= mod;
    while (b) {
        if (b & 1) x = (x * a) % mod; 
        a = (a * a) % mod;
        b >>= 1;
    }
    return x;
}



vector<int> fact(N);
vector<int> ifact(N);


void computeFactorial(int mod){
	fact[0] = ifact[0] = 1;
	for(int i=1; i<N; i++){
		fact[i] = (fact[i-1] * i)% mod;
	}


	ifact[N-1] = power(fact[N-1], mod-2, mod);
	for(int i = N-2; i>=1; i--){
		ifact[i] = (ifact[i+1] * (i+1))%mod;
	}
}

int nCr(int n, int r, int mod){
	if(r>n || r<0) return 0;
	return ( ( fact[n] * ifact[r] )%mod * ifact[n-r] ) % mod;
}



//_ ***************************** START Below *******************************


int MOD = 998244353;


vector<int> a;

int consistency(int n){

    computeFactorial(MOD);

    int ways = 1;
    for(int i=0; i<=n-3; i+=3){
        vector<int> triad = {a[i], a[i+1], a[i+2]};
        sort(begin(triad), end(triad), greater<int>());
        
        if(triad[0] == triad[2]){
            ways = (ways*3)%MOD;
        }
        else if(triad[0] != triad[1] && triad[1] == triad[2] ){
            ways = (ways*2)%MOD;
        }
        else ways *= 1;
    }

    int t = n/3; // total triads t
    int totalWays = (nCr(t, t/2, MOD) * ways)%MOD;


    return totalWays;
}















int practice(int n){


    return 0;
}





void solve() {
    
    int n;
    cin>> n;
    
    a.resize(n);
    for(int i=0; i<n; i++) cin >> a[i];
    
    cout << consistency(n) << endl;


}





int32_t main() {
    ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);

    int t = 1;
    // cin >> t;
    while (t--) {
        solve();
    }

    return 0;
}