#include <bits/stdc++.h> 
using namespace std;
using ll =long long;
#define all(v) v.begin(),v.end()
 #define rep(i,a,b) for(int i=a;i<b;i++)
#define rrep(i,a,b) for(int i=a;i>=b;i--)

ll mod=998244353;


ll mod_pow(ll x,ll n,ll mod) {
ll res=1;
  while(n>0) {
if(n&1) {
res=res*x%mod;
}
   x=x*x%mod;
    n>>=1;
  }
return res;
}


int main() {
 ll N,K;cin>>N>>K;
 vector<ll> A(N);
 for(ll i=0;i<N;i++) cin>>A[i];

ll s=0;
for(ll i=0;i<N;i++) s+=A[i];
ll E=1;
E*=s;
E%=mod;

ll ans=mod_pow(2,K,mod)-1;
ans%=mod;
ans*=E;
ans%=mod;
if(ans<0) ans+=mod;
ans+=s;
ans%=mod;

cout<<ans<<endl;
}