#include <bits/stdc++.h>

#include <atcoder/all>
using namespace std;
using i32 = int;
using u32 = unsigned int;
using i64 = long long;
using u64 = unsigned long long;
#define FAST_IO                \
  ios::sync_with_stdio(false); \
  cin.tie(0);
const i64 INF = 1001001001001001001;
using Modint = atcoder::static_modint<998244353>;

int main() {
  FAST_IO

  int N;
  cin >> N;
  vector<i64> c(N);
  for (auto& x : c) cin >> x;

  if (c[0] < 0 && c[N-1] > 0) {
    int neg = 0;
    int pos = 0;
    int zero = 0;
    for (int i = 0; i < N; i ++) {
      if (c[i] < 0) {
        neg ++;
      } else if (c[i] > 0) {
        pos ++;
      } else {
        zero ++;
      }
    }
    Modint ans = 2;
    ans *= Modint(2).pow(neg - 1);
    ans *= Modint(2).pow(pos - 1);
    if (zero > 0) {
      ans *= 3;
    }
    cout << ans.val() << endl;
  } else if (N >= 2) {
    Modint ans = 0;
    int zero = 0;
    int other = 0;
    for (int i = 0; i < N; i ++) {
      if (c[i] == 0) {
        zero ++;
      } else {
        other ++;
      }
    }
    ans = Modint(2).pow(other - 1);
    if (zero > 0) {
      ans *= 2;
    }
    cout << ans.val() << endl;
  } else {
    cout << 1 << endl;
  }

}