func_code_string: #include <bits/stdc++.h>   using namespace std;   const int N = 6e5 + 5, mod = 998244353;   vector<int> num;   long long A[N];   int a[N];   long long sumup = 0, sumdown = 0;   long long qpow(long long a, long long b) {     long long c = 1;     while (b) {       if (b & 1) c = (a * c) % mod;       b >>= 1;       a = (a * a) % mod;     }     return c;   }   long long inv(long long x) { return qpow(x, mod - 2); }   int main() {     int n;     cin >> n;     n <<= 1;     A[0] = 1;     for (int i = 1; i <= n; i++) A[i] = (A[i - 1] * i) % mod;     for (int i = 1; i <= n; i++) cin >> a[i];     long long ans = 0;     sort(a + 1, a + n + 1);     for (int i = 1; i <= n / 2; i++) ans -= a[i];     for (int i = n / 2 + 1; i <= n; i++) ans += a[i];     ans = (ans % mod * A[n] % mod * inv(A[n / 2]) % mod * inv(A[n / 2])) % mod;     cout << ans << endl;   }   