#include <bits/stdc++.h>   using namespace std;   const int N = 500005;   const int M = 998244353;   int n, a[N], i, s;   long long f[N], c[N], x, y, z, ans[N], tp;   long long qpow(long long a, long long b) {     long long s = a, ans = 1;     while (b) {       if (b & 1) ans = ans * s % M;       s = s * s % M;       b >>= 1;     }     return ans;   }   int main() {     scanf( %d , &n);     for (i = 1; i <= n; ++i) {       scanf( %d , &a[i]);       s += a[i];     }     long long is = qpow(s, M - 2), in = qpow(n - 1, M - 2);     c[1] = 1 - n;     f[0] = f[1] = 1;     for (i = 1; i < s; ++i) {       x = i * is % M, y = (s - i) * is % M * in % M;       z = qpow(y, M - 2);       f[i + 1] = (f[i] * (x + y) - f[i - 1] * x) % M * z % M;       c[i + 1] = (c[i] * (x + y) - 1 - c[i - 1] * x) % M * z % M;     }     ans[0] = -c[s] * qpow(f[s], M - 2) % M;     for (i = 1; i < s; ++i) ans[i] = (f[i] * ans[0] + c[i]) % M;     for (i = 1; i <= n; ++i) tp += ans[a[i]];     tp -= ans[0] * (n - 1);     cout << (tp % M * qpow(n, M - 2) % M + M) % M;   }   