• 注意：子序列不需要连续，所以数组的顺序无关紧要，那我们不妨先把数组排序
• 排序后，如果 $a_i$ 能作为某个子序列的最小值，那这样的子序列有多少个呢？

#include <bits/stdc++.h>
using namespace std;

using i64 = long long;
const int P = 998244353;

int solve(vector<int>& a) {
    int n = a.size();
    sort(a.begin(), a.end());
    
    vector<int> b(n, 1);
    for (int i = 1; i < n; i++) b[i] = b[i - 1] * 2 % P;

    i64 ans = 0;
    for (int i = 0; i < n; i++) {
        ans = (ans + (i64) a[i] * b[i] - (i64) a[i] * b[n - 1 - i]) % P;
    }
    return ans;
}

int main() {	
    ios::sync_with_stdio(false);
    cin.tie(0); cout.tie(0);

    int n;
    cin >> n;
    vector<int> a(n);
    for (int i = 0; i < n; i++) cin >> a[i];
    cout << solve(a) << '\n';

    return 0;
}