#include <bits/stdc++.h>
using namespace std;
#include <atcoder/all>
using namespace atcoder;
using mint = atcoder::static_modint<998244353>;
// using mint = atcoder::static_modint<1000000007>;
using ld = long double;
using ll = long long;
#define mp(a,b) make_pair(a,b)
#define rep(i,s,n) for(int i=s; i<(int)n; i++)
using vl = vector<ll>;
using vvl = vector<vl>;
using vvvl = vector<vvl>;
using vvvvl = vector<vvvl>;
const vector<int> dx{1,0,-1,0},dy{0,1,0,-1};

int main(){
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    int n;cin >> n;
    int pos=0,nega=0,zero=0;
    rep(i,0,n){
        int x;cin >> x;
        if(x>0)pos++;
        else if(x<0)nega++;
        else zero++;
    }
    mint ans=1;
    if(pos>0)ans*=mint(2).pow(pos-1);
    if(nega>0)ans*=mint(2).pow(nega-1);
    
    int c=0;
    if(pos>0)c++;
    if(nega>0)c++;
    if(zero>0)c++;

    rep(i,1,c+1)ans*=i;
    cout << ans.val();
}