import std;

void main () {
    int N = readln.chomp.to!int;
    auto c = readln.split.to!(int[]);
    const long MOD = 998244353;

    int minus = 0, plus = 0;
    bool zero = false;
    foreach (v; c) {
        if (v < 0) minus++;
        if (0 < v) plus++;
        if (v == 0) zero = true;
    }

    if (minus == 0 && plus == 0) {
        writeln(1);
        return;
    }
    if (minus == 0) {
        long ans = mod_pow(2, plus - 1, MOD);
        if (zero) {
            ans *= 2;
            ans %= MOD;
        }
        writeln(ans);
    }
    if (plus == 0) {
        long ans = mod_pow(2, minus - 1, MOD);
        if (zero) {
            ans *= 2;
            ans %= MOD;
        }
        writeln(ans);
    }

    long ans = 0;
    long m = mod_pow(2, minus - 1, MOD);
    long p = mod_pow(2, plus - 1, MOD);

    // plus -> minus
    // minus -> plus
    // が基本パターンで、0をとるタイミングは各3箇所

    ans = 2 * m * p % MOD;

    if (zero) {
        ans *= 3;
        ans %= MOD;
    }

    writeln(ans);
}

void read (T...) (string S, ref T args) {
    import std.conv : to;
    import std.array : split;
    auto buf = S.split;
    foreach (i, ref arg; args) {
        arg = buf[i].to!(typeof(arg));
    }
}

long mod_pow (long a, long x, const long MOD)
in {
    assert(0 <= x, "x must satisfy 0 <= x");
    assert(1 <= MOD, "MOD must satisfy 1 <= MOD");
    assert(MOD <= int.max, "MOD must satisfy MOD*MOD <= long.max");
}
do {
    // normalize
    a %= MOD; a += MOD; a %= MOD;

    long res = 1L;
    long base = a;
    while (0 < x) {
        if (0 < (x&1)) (res *= base) %= MOD;
        (base *= base) %= MOD;
        x >>= 1;
    }

    return res % MOD;
}