#include <stdio.h>

int main () {
  int n = 0;
  long long a[200000] = {};
  
  int res = 0;
  
  long long ans = 0LL;
  long long mod_num = 998244353LL;
  
  long long pow2[200001] = {};
  
  res = scanf("%d", &n);
  for (int i = 0; i < n; i++) {
    res = scanf("%lld", a+i);
  }
  
  pow2[0] = 1LL;
  for (int i = 0; i < n; i++) {
    pow2[i+1] = pow2[i]*2LL;
    pow2[i+1] %= mod_num;
  }
  
  for (int i = 0; i < n; i++) {
    long long tmp = a[i];
    if (i > 0) {
      tmp *= (pow2[i]+((long long)i)*pow2[i-1])%mod_num;
      tmp %= mod_num;
    }
    if (i < n-1) {
      tmp *= (pow2[n-i-1]+((long long)(n-i-1))*pow2[n-i-2])%mod_num;
      tmp %= mod_num;
    }
    ans += tmp;
  }
  
  printf("%lld\n", ans%mod_num);
  return 0;
}