#include <stdio.h>

long long power_mod (long long a, long long b, long long mod_num) {
  long long ans = 1LL;
  
  if (b > 0LL) {
    ans = power_mod(a, b/2LL, mod_num);
    ans = (ans * ans) % mod_num;
    if (b%2LL > 0LL) {
      ans = (ans * (a % mod_num)) % mod_num;
    }
  }
  
  return ans;
}

int main () {
  int n = 0;
  long long a[200000] = {};
  
  int res = 0;
  
  long long ans = 0LL;
  long long mod_num = 998244353LL;
  
  long long fact[400001] = {};
  long long invf[400001] = {};
  
  res = scanf("%d", &n);
  for (int i = 0; i < n; i++) {
    res = scanf("%lld", a+i);
  }
  
  fact[0] = 1LL;
  for (int i = 0; i < 2*n; i++) {
    fact[i+1] = (fact[i]*((long long)i+1))%mod_num;
  }
  
  invf[2*n] = power_mod(fact[2*n], mod_num-2LL, mod_num);
  for (int i = 2*n; i > 0; i--) {
    invf[i-1] = (invf[i]*((long long)i))%mod_num;
  }
  
  for (int i = 0; i < n; i++) {
    long long tmp = (fact[2*n-2-i]*invf[n-i-1])%mod_num;
    tmp *= invf[n-1];
    tmp %= mod_num;
    if (n-i > 1) {
      long long tmp2 = (fact[2*n-2-i]*invf[n-i-2])%mod_num;
      tmp += mod_num-(tmp2*invf[n])%mod_num;
      tmp %= mod_num;
    }
    ans += a[i]*tmp;
    ans %= mod_num;
  }
  
  printf("%lld\n", ans);
  return 0;
}