#include <bits/stdc++.h>
using namespace std;
#define int long long
const int mod = 998244353;
vector<long long> fact, fact_inv, inv;
void init_nCk(int SIZE) {
    fact.resize(SIZE + 5);
    fact_inv.resize(SIZE + 5);
    inv.resize(SIZE + 5);
    fact[0] = fact[1] = 1;
    fact_inv[0] = fact_inv[1] = 1;
    inv[1] = 1;
    for (int i = 2; i < SIZE + 5; i++) {
        fact[i] = fact[i - 1] * i % mod;
        inv[i] = mod - inv[mod % i] * (mod / i) % mod;
        fact_inv[i] = fact_inv[i - 1] * inv[i] % mod;
    }
}
long long nCk(int n, int k) {
    if(n < k || n < 0 || k < 0) return 0;
    return fact[n] * (fact_inv[k] * fact_inv[n - k] % mod) % mod;
}
signed main(){
    init_nCk(500100);
    int N;
    cin>>N;
    int a = 0, b = 0, c = 0;
    vector<int> I(N+5);
    I[0] = 1;
    for(int i=0;i<N+3;i++) I[i+1] = I[i]*2%mod;
    for(int i=0;i<N;i++){
    	int x;
    	cin>>x;
    	if(x < 0) a++;
    	if(x == 0) b++;
    	if(x > 0) c++;
    }
    if(N == 1){
    	cout<<1<<endl;
    	return 0;
    }
    int ans = (a != 0)+(c != 0);
    ans *= I[max(0ll,a-1)]%mod*I[max(0ll,c-1)]%mod;
    ans %= mod;
    cout<<(b ? b+(a != 0)+(c != 0) : 1)*ans%mod<<endl;
}