#include using namespace std; long long mod = 998244353; //入力が必ず-mod= mod) v -= mod; return *this; } mint operator-=(const mint b){ v -= b.v; if(v < 0) v += mod; return *this; } mint operator*=(const mint b){v = v*b.v%mod; return *this;} mint operator/=(mint b){ if(b == 0) assert(false); int left = mod-2; while(left){if(left&1) *this *= b; b *= b; left >>= 1;} return *this; } mint operator++(){*this += 1; return *this;} mint operator--(){*this -= 1; return *this;} mint operator++(int){*this += 1; return *this;} mint operator--(int){*this -= 1; return *this;} bool operator==(const mint b){return v == b.v;} bool operator!=(const mint b){return v != b.v;} bool operator>(const mint b){return v > b.v;} bool operator>=(const mint b){return v >= b.v;} bool operator<(const mint b){return v < b.v;} bool operator<=(const mint b){return v <= b.v;} mint pow(long long n){ mint ret = 1,p = v; if(n < 0) p = p.inv(),n = -n; while(n){ if(n&1) ret *= p; p *= p; n >>= 1; } return ret; } mint inv(){return mint(1)/v;} }; int main() { ios_base::sync_with_stdio(false); cin.tie(nullptr); int N; cin >> N; string s; cin >> s; int Limit = N; //Limit 必要なサイズ fac->x! facinv->1/x! inv->1/x. vector fac(Limit+1,1); for(int i=1; i<=Limit; i++) fac.at(i) = fac.at(i-1)*i; vector facinv(Limit+1); facinv.at(min((int)mod-1,Limit)) = fac.at(min((int)mod-1,Limit)).inv(); for(int i=min((int)mod-2,Limit-1); i>=0; i--) facinv.at(i) = facinv.at(i+1)*(i+1); //vector inv(Limit+1); for(int i=1; i<=Limit; i++) inv.at(i) = fac.at(i-1)*facinv.at(i); //必要なら解放!. auto nCr = [&](int n, int r) -> mint { if(n < r || r < 0 || n < 0) return 0; return fac.at(n)*facinv.at(r)*facinv.at(n-r); }; mint answer = 0; if(s.at(1) == '('){ for(int i=0; i<=N/2; i++) answer += nCr(N/2,i)*nCr(N/2,i); } else answer = mint(2).pow(N/2); cout << answer.v << endl; }