#include<bits/stdc++.h>
using namespace std;
#define int long long
#define REP(i,m,n) for(int i=(m);i<(n);i++)
#define rep(i,n) REP(i,0,n)
#define pb push_back
#define all(a) a.begin(),a.end()
#define rall(c) (c).rbegin(),(c).rend()
#define mp make_pair
#define endl '\n'
#define vec vector<ll>
#define mat vector<vector<ll> >
#define fi first
#define se second
typedef long long ll;
typedef unsigned long long ull;
typedef pair<ll,ll> pll;
typedef long double ld;
typedef complex<double> comp;
const ll inf=1e9+7;
const ll mod=998244353;
const int MAX=300010;

ll rui(ll a,ll b){
    ll res=1;
    ll x=a;
    while(b){
        if(b&1)res=res*x%mod;
        x=x*x%mod;
        b/=2;
    }
    return res;
}

signed main(){
    string s;cin>>s;
    ll n=s.size();
    vector<ll>a(26);
    rep(i,n){
        a[s[i]-'a']++;
    }
    vector<ll>kai(n+1);
    kai[0]=1;
    REP(i,1,n+1){
        kai[i]=kai[i-1]*i%mod;
    }
    vector<ll>inv(n+1);
    rep(i,n+1){
        inv[i]=rui(kai[i],mod-2);
    }
    vector<vector<ll> >dp(27,vector<ll>(n+1));
    dp[0][0]=1;
    rep(i,26){
        rep(j,n+1){
            if(dp[i][j]==0)continue;
            rep(k,a[i]+1){
                if(k+j<=n){
                    dp[i+1][k+j]=(dp[i][j]*inv[k]%mod+dp[i+1][k+j])%mod;
                }
            }
        }
    }
    ll ans=0;
    REP(i,1,n+1){
        ans=(ans+kai[i]*dp[26][i]%mod)%mod;
    }
    cout<<ans<<endl;
}