#include #pragma GCC optimize("Ofast") #define _GLIBCXX_DEBUG using namespace std; using std::cout; using std::cin; using std::endl; using ll=long long; using ld=long double; ll ILL=1167167167167167167; const int INF=2100000000; const ll mod=998244353; #define rep(i,a) for (ll i=0;i using _pq = priority_queue, greater>; template ll LB(vector &v,T a){return lower_bound(v.begin(),v.end(),a)-v.begin();} template ll UB(vector &v,T a){return upper_bound(v.begin(),v.end(),a)-v.begin();} template bool chmin(T &a,const T &b){if(a>b){a=b;return 1;}else return 0;} template bool chmax(T &a,const T &b){if(a void So(vector &v) {sort(v.begin(),v.end());} template void Sore(vector &v) {sort(v.begin(),v.end(),[](T x,T y){return x>y;});} void yneos(bool a){if(a) cout<<"Yes\n"; else cout<<"No\n";} template void vec_out(vector &p){for(int i=0;i<(int)(p.size());i++){if(i) cout<<" ";cout< using square_matrix=std::vector>; template square_matrix mul_matrix(square_matrix l,square_matrix r){ int n=l.size(); assert((int)l[0].size()==n&&(int)r.size()==n&&(int)r[0].size()==n); square_matrix val(n,std::vector(n,add_e())); for(int i=0;i square_matrix pow_matrix(square_matrix l,long long times){ int n=l.size(); square_matrix val(n,std::vector(n,add_e())); for(int i=0;i(val,l); } l=mul_matrix(l,l); times>>=1; } return val; } using mat_F=ll; mat_F add_op(mat_F a,mat_F b){ return (a+b)%mod; } mat_F add_e(){ return 0; } mat_F mul_op(mat_F a,mat_F b){ return (a*b)%mod; } mat_F mul_e(){ return 1; } #define calc mat_F,add_op,add_e,mul_op,mul_e void solve(); // oddloop int main() { ios::sync_with_stdio(false); cin.tie(nullptr); int t=1; //cin>>t; rep(i,t) solve(); } void solve(){ string S; int K; cin>>S>>K; int N=(int)(S.size())/2; square_matrix base(N+1,vector(N+1)); rep(i,N+1){ ll A=i*i,B=(N-i)*(N-i); if(i!=0){ base[i][i-1]=A; } if(i!=N) base[i][i+1]=B; base[i][i]=N*(2*N-1)-A-B; } base=pow_matrix(base,K); vector> dp(N+2,vector(N+2)); auto em=dp; dp[0][0]=1; rep(i,N*2){ auto n_dp=em; rep(j,N+1) rep(k,N+1){ dp[j][k]%=mod; if(dp[j][k]==0) continue; if(j!=0){ if(S[i]=='(') n_dp[j-1][k+1]+=dp[j][k]; else n_dp[j-1][k]+=dp[j][k]; } n_dp[j+1][k]+=dp[j][k]; } swap(n_dp,dp); } ll ans=0; rep(i,N+1){ dp[0][i]%=mod; ans+=(dp[0][i]*base[i][0])%mod; ans%=mod; } cout<