// constexpr ll mod = 998244353;
// vector<ll> mul(const vector<ll> &a, const vector<ll> &b){
// 	vector<ll> c(sz(a) + sz(b) - 1);
// 	for(int i = 0; i < sz(a); i++){
// 		for(int j = 0; j < sz(b); j++){
// 			c[i+j] += a[i]*b[j] % mod;
// 		}
// 	}
// 	for(ll &x : c) x %= mod;
// 	return c;
// }

ll kthTerm(const vector<ll>& f, const vector<ll>& c, ll k) {
	int n = sz(c);
	vector<ll> q(n + 1, 1);
	for (int i = 0; i < n; i++) q[i + 1] = (mod - c[i])%mod;
	vector<ll> p = mul(f, q);
	p.resize(n);
	p.push_back(0);
	do {
		vector<ll> q2 = q;
		for (int i = 1; i <= n; i += 2) q2[i] = (mod - q2[i]) % mod;
		vector<ll> x = mul(p, q2), y = mul(q, q2);
		for (int i = 0; i <= n; i++){
			p[i] = i == n ? 0 : x[2*i + (k&1)];
			q[i] = y[2*i];
		}
	} while (k /= 2);
	return p[0];
}