#include <iostream>
#include <vector>
using namespace std;

#define PB push_back
typedef long long int ll;
constexpr int kN = 1 << 20, kMod = 998244353;

ll Pow(ll a, ll b) {
	ll ans = 1;
	while (b) {
		if (b & 1) ans = ans * a % kMod;
		a = a * a % kMod;
		b >>= 1;
	}
	return ans;
}

ll Rev(ll n) {return Pow(n, kMod - 2);}

void Ntt(vector<ll> &v, bool on, int size);

int cnt[26];
ll f[kN], inf[kN];
vector<ll> v[26];

void pre() {
	f[0] = f[1] = inf[0] = inf[1] = 1;
	for (int i = 2; i < kN; i++) f[i] = f[i - 1] * i % kMod;
	inf[kN - 1] = Rev(f[kN - 1]);
	for (int i = kN - 1; i > 2; i--) inf[i - 1] = inf[i] * i % kMod;
	for (int i = 0; i < 26; i++) v[i].resize(kN, 0);
	return ;
}

int main() {
	string s;
	ll ans = kMod - 1;
	cin >> s;
	for (char i : s) cnt[i - 'a']++;
	pre();
	for (int i = 0; i < 26; i++) for (int j = 0; j <= cnt[i]; j++) v[i][j] = inf[j];
	for (int i = 0; i < 26; i++) Ntt(v[i], false, kN);
	for (int i = 1; i < 26; i++) for (int j = 0; j < kN; j++) v[0][j] = v[0][j] * v[i][j] % kMod;
	Ntt(v[0], true, kN);
	for (int i = 0; i < kN; i++) ans += v[0][i] * f[i] % kMod;
	cout << ans % kMod << '\n';
}

void Ntt(
  vector<long long int> &v, bool on, int size) {
  long long int wn, u, t, w, inv;
  for (int i = 1, j = size >> 1, k; i < (size - 1);
       i++) {
    if (i < j) swap(v[i], v[j]);
    k = size >> 1;
    while (j & k) {
      j ^= k;
      k >>= 1;
    }
    j |= k;
  }
  for (int i = 2; i <= size; i <<= 1) {
    wn = on ? Pow(3, (kMod - 1) / i) :
              Pow(3, kMod - 1 - (kMod - 1) / i);
    for (int j = 0; j < size; j += i) {
      w = 1;
      for (int k = j; k < j + (i >> 1); k++) {
        u = v[k];
        t = (w * v[k + (i >> 1)]) % kMod;
        v[k] = (u + t) % kMod;
        v[k + (i >> 1)] = (u - t + kMod) % kMod;
        w = (w * wn) % kMod;
      }
    }
  }
  if (on) {
    inv = Rev(size);
    for (int i = 0; i < size; i++)
      v[i] = (v[i] * inv) % kMod;
  }
  return;
}