//Let's join Kaede Takagaki Fan Club !! #pragma GCC optimize("Ofast") #pragma GCC optimize("unroll-loops") #include #include #include using namespace std; typedef long long ll; typedef pair P; typedef pair P1; typedef pair P2; #define pu push #define pb push_back #define mp make_pair #define eps 1e-7 #define INF 1000000000 #define fi first #define sc second #define rep(i,x) for(int i=0;i void dmp(T a){ rep(i,a.size()) cout << a[i] << " "; cout << endl; } template bool chmax(T&a, T b){ if(a < b){ a = b; return 1; } return 0; } template bool chmin(T&a, T b){ if(a > b){ a = b; return 1; } return 0; } template void g(T &a){ cin >> a; } template void o(const T &a,bool space=false){ cout << a << (space?' ':'\n'); } //ios::sync_with_stdio(false); const ll mod = 998244353; template void add(T&a,T b){ a+=b; if(a >= mod) a-=mod; } template struct ntt{ inline void add(int &a, int b) { a += b; if(a >= md) a -= md; } inline void sub(int &a, int b) { a -= b; if(a < 0) a += md; } inline int mul(int a, int b) { return (int)((ll)a*b%md); } inline int power(int a, long long b) { int res = 1; while (b > 0) { if (b & 1) res = mul(res, a); a = mul(a, a); b >>= 1; } return res; } inline int inv(int a) { a %= md; if (a < 0) a += md; int b = md, u = 0, v = 1; while (a) { int t = b / a; b -= t * a; swap(a, b); u -= t * v; swap(u, v); } assert(b == 1); if (u < 0) u += md; return u; } int max_base, root; vector dw, idw; ntt() { int tmp = md - 1; max_base = 0; while (tmp % 2 == 0) { tmp /= 2; max_base++; } root = 2; while (power(root, (md-1)>>1) == 1) root++; dw.resize(max_base); idw.resize(max_base); rep(i, max_base){ sub(dw[i], power(root, (md-1) >> (i+2))); idw[i] = inv(dw[i]); } } void fft(vector &a, bool inv) { const int n = a.size(); assert((n & (n - 1)) == 0); assert(__builtin_ctz(n) <= max_base); if(!inv){ for(int m=n;m>>=1;){ int w = 1; for(int s=0,k=0; s=y?x-y:x+md-y); a[i] = (x+y>=md?x+y-md:x+y); } w = mul(w, dw[__builtin_ctz(++k)]); } } } else{ for(int m=1;m=y?x-y:x+md-y); a[j] = mul(a[j], w); a[i] = (x+y>=md?x+y-md:x+y); } w = mul(w, idw[__builtin_ctz(++k)]); } } } } vector multiply(vector a, vector b, int eq = 0) { int need = a.size() + b.size() - 1; int nbase = 0; while ((1 << nbase) < need) nbase++; int sz = 1 << nbase; a.resize(sz); b.resize(sz); fft(a, 0); if (eq) b = a; else fft(b, 0); int inv_sz = inv(sz); for (int i = 0; i < sz; i++) { a[i] = mul(mul(a[i], b[i]), inv_sz); } fft(a, 1); a.resize(need); return a; } vector square(vector a) { return multiply(a, a, 1); } }; ntt<998244353>kaede; string s; int cnt[26]; vectorvec[26]; ll modpow(ll x,ll n){ ll res=1; while(n>0){ if(n&1) res=res*x%mod; x=x*x%mod; n>>=1; } return res; } ll F[300005],R[300005]; void make(){ F[0] = 1; for(int i=1;i<300005;i++) F[i] = F[i-1]*i%mod; for(int i=0;i<300005;i++) R[i] = modpow(F[i],mod-2); } ll C(int a,int b){ return F[a]*R[b]%mod*R[a-b]%mod; } vectorcalc(int a, int b){ if(a == b) return vec[a]; auto L = calc(a, (a+b)/2); auto R = calc((a+b)/2+1, b); return kaede.multiply(L, R); } int main(){ make(); cin >> s; rep(i, s.size()) cnt[s[i]-'a']++; rep(i, 26){ rep(j, cnt[i]+1){ vec[i].pb((int)(R[j])); } } auto ret = calc(0, 25); ll ans = 0; rep(i, ret.size()){ ans += (ll)(ret[i]) * F[i] % mod; } ans += mod-1; cout << ans%mod << endl; }