#include //#include using namespace std; #define all(a)a.begin(),a.end() using ll=long long; const int INF = 1<<30; const ll INFll =1LL<<62; //const int mod= int(1e9)+7; const int mod2=998244353; using P = pair; using Pl= pair; using ld=long double; using V=vector; using Vl=vector; using Vd=vector; using VV=vector>; using VVl=vector>; using VVd=vector>; //using mint=atcoder::modint1000000007; // modint: mod 計算を int を扱うように扱える構造体 template struct Fp { long long val; constexpr Fp(long long v = 0) noexcept : val(v % MOD) { if (val < 0) val += MOD; } constexpr int getmod() { return MOD; } constexpr Fp operator - () const noexcept { return val ? MOD - val : 0; } constexpr Fp operator + (const Fp& r) const noexcept { return Fp(*this) += r; } constexpr Fp operator - (const Fp& r) const noexcept { return Fp(*this) -= r; } constexpr Fp operator * (const Fp& r) const noexcept { return Fp(*this) *= r; } constexpr Fp operator / (const Fp& r) const noexcept { return Fp(*this) /= r; } constexpr Fp& operator += (const Fp& r) noexcept { val += r.val; if (val >= MOD) val -= MOD; return *this; } constexpr Fp& operator -= (const Fp& r) noexcept { val -= r.val; if (val < 0) val += MOD; return *this; } constexpr Fp& operator *= (const Fp& r) noexcept { val = val * r.val % MOD; return *this; } constexpr Fp& operator /= (const Fp& r) noexcept { long long a = r.val, b = MOD, u = 1, v = 0; while (b) { long long t = a / b; a -= t * b; swap(a, b); u -= t * v; swap(u, v); } val = val * u % MOD; if (val < 0) val += MOD; return *this; } constexpr bool operator == (const Fp& r) const noexcept { return this->val == r.val; } constexpr bool operator != (const Fp& r) const noexcept { return this->val != r.val; } friend constexpr ostream& operator << (ostream &os, const Fp& x) noexcept { return os << x.val; } friend constexpr Fp modpow(const Fp &a, long long n) noexcept { if (n == 0) return 1; auto t = modpow(a, n / 2); t = t * t; if (n & 1) t = t * a; return t; } }; using mint = Fp; ll modpow(ll N, ll P){ if(P==0) return 1; if(P%2==0){ ll t =modpow(N, P/2); return t*t % mod2; } return N * modpow(N, P-1)%mod2; } int main() { ios::sync_with_stdio(false); cin.tie(nullptr); ll n,k;cin >>n>>k; mint ans=0; for (int i = 0; i < n; ++i) { ld a;cin >>a; ans+=a; } ans/=n; ans*=modpow(2,k); cout <