#include //#include //#pragma GCC optimize("Ofast") using namespace std; #define reps(i,s,n) for(int i = s; i < n; i++) #define rep(i,n) reps(i,0,n) #define Rreps(i,n,e) for(int i = n - 1; i >= e; --i) #define Rrep(i,n) Rreps(i,n,0) #define ALL(a) a.begin(), a.end() #define fi first #define se second typedef long long ll; typedef vector vec; typedef vector mat; ll N,M,H,W,Q,K,A,B; string S; typedef pair P; const ll INF = (1LL<<58); class mint{ public: ll x; static unsigned long long mod; static unsigned long long mod_plus; mint(){x = 0;} mint(ll _x) : x((_x < 0 ? ((_x += mod_plus) < 0 ? _x + mod_plus : _x) : _x)%mod){} /*mint& operator=(const ll &a){ x = a; return *this; }*/ mint operator-(){ return x == 0 ? 0 : mod - x; } mint& operator+=(const mint& a){ if((x += a.x) >= mod) x -= mod; return *this; } mint operator+(const mint& a) const{ mint res(*this); return res += a; } mint& operator-=(const mint& a){ if((x -= a.x) < 0) x += mod; return *this; } mint operator-(const mint& a) const{ mint res(*this); return res -= a; } mint& operator*=(const mint& a){ (x *= a.x)%=mod; return *this; } /*mint& operator*=(const ll& a){ mint temp(a); return *this *= temp; }*/ mint operator*(const mint& a) const{ mint res(*this); return res *= a; } /*mint operator*(const ll& a) const{ mint res(*this); return res *= a; }*/ mint pow(unsigned long long pw) const{ mint res(1), comp(*this); while(pw){ if(pw&1) res *= comp; comp *= comp; pw >>= 1; } return res; } //以下、modが素数のときのみ mint inv() const{ mint res(*this); return res.pow(mod - 2); } mint& operator/=(const mint &a){ (x *= a.inv().x)%=mod; return *this; } mint operator/(const mint &a) const{ mint res(*this); return res /= a; } }; ostream& operator<<(ostream& os, const mint& a){ os << a.x; return os; } unsigned long long mint::mod = 998244353; //unsigned long long mint::mod = int(1e+9) + 7; unsigned long long mint::mod_plus = (LLONG_MAX / mint::mod) * mint::mod; typedef vector vm; const ll MAX_N = ll(4e+5) + 10; vm fact(MAX_N, mint(1)), fact_inv(MAX_N, mint(1)); void makefact(){ reps(i,2,MAX_N) { fact[i] = fact[i-1] * mint(i); fact_inv[i] = fact[i].inv(); } } mint nCm(ll n, ll m){ return fact[n] * fact_inv[n-m] * fact_inv[m]; } mint nCm_inv(ll n, ll m){ return fact[n-m] * fact[m] * fact_inv[n]; } int main() { makefact(); cin>>S; N = S.size(); vec num(26, 0); for(char c : S) ++num[c - 'a']; vector dp(27, vm(N + 1, 0)); dp[0][0] = 1; rep(i, 26){ rep(j, N + 1){ for(int k = 0; k <= num[i] && j + k <= N; ++k){ dp[i + 1][j + k] += dp[i][j] * fact_inv[k]; } } } mint ans(0); reps(i, 1, N + 1) ans += dp[26][i] * fact[i]; cout<