def Primitive_Root(p):
    """Z/pZ上の原始根を見つける

    p:素数
    """
    if p==2:
        return 1
    if p==998244353:
        return 3
    if p==10**9+7:
        return 5
    if p==163577857:
        return 23
    if p==167772161:
        return 3
    if  p==469762049:
        return 3

    fac=[]
    q=2
    v=p-1

    while v>=q*q:
        e=0
        while v%q==0:
            e+=1
            v//=q

        if e>0:
            fac.append(q)
        q+=1

    if v>1:
        fac.append(v)

    g=2
    while g<p:
        if pow(g,p-1,p)!=1:
            return None

        flag=True
        for q in fac:
            if pow(g,(p-1)//q,p)==1:
                flag=False
                break

        if flag:
            return g

        g+=1

#参考元 https://atcoder.jp/contests/practice2/submissions/16789717
def NTT(A):
    """AをMod を法とする数論変換を施す

    ※Modはグローバル変数から指定
    """
    primitive=Primitive_Root(Mod)

    N=len(A)
    H=(N-1).bit_length()

    if Mod==998_244_353:
        m=998_244_352
        u=119
        e=23
        S=[1,998244352,911660635,372528824,929031873,
        452798380,922799308,781712469,476477967,166035806,
        258648936,584193783,63912897,350007156,666702199,
        968855178,629671588,24514907,996173970,363395222,
        565042129,733596141,267099868,15311432]
    else:
        m=Mod-1
        e=((m&-m)-1).bit_length()
        u=m>>e
        S=[pow(primitive,(Mod-1)>>i,Mod) for i in range(e+1)]

    for l in range(H, 0, -1):
        d = 1 << l - 1
        U = [1]*(d+1)
        u = 1
        for i in range(d):
            u=u*S[l]%Mod
            U[i+1]=u

        for i in range(1 <<H - l):
            s=2*i*d
            for j in range(d):
                A[s],A[s+d]=(A[s]+A[s+d])%Mod, U[j]*(A[s]-A[s+d])%Mod
                s+=1

#参考元 https://atcoder.jp/contests/practice2/submissions/16789717
def Inverse_NTT(A):
    """AをMod を法とする逆数論変換を施す

    ※Modはグローバル変数から指定
    """
    primitive=Primitive_Root(Mod)

    N=len(A)
    H=(N-1).bit_length()

    if Mod==998244353:
        m=998_244_352
        e=23
        u=119
        S=[1,998244352,86583718,509520358,337190230,
        87557064,609441965,135236158,304459705,685443576,
        381598368,335559352,129292727,358024708,814576206,
        708402881,283043518,3707709,121392023,704923114,950391366,
        428961804,382752275,469870224]
    else:
        m=Mod-1
        e=(m&-m).bit_length()-1
        u=m>>e

        inv_primitive=pow(primitive,Mod-2,Mod)
        S=[pow(inv_primitive,(Mod-1)>>i,Mod) for i in range(e+1)]

    for l in range(1, H + 1):
        d = 1 << l - 1
        for i in range(1 << H - l):
            u = 1
            for j in range(2*i*d, (2*i+1)*d):
                A[j+d] *= u
                A[j], A[j+d] = (A[j] + A[j+d]) % Mod, (A[j] - A[j+d]) % Mod
                u = u * S[l] % Mod

    N_inv=pow(N,Mod-2,Mod)
    for i in range(N):
        A[i]=A[i]*N_inv%Mod

#参考元 https://atcoder.jp/contests/practice2/submissions/16789717
def Convolution_Mod(A,B):
    """A,BをMod を法とする畳み込みを求める.

    ※Modはグローバル変数から指定
    """
    if not A or not B:
        return []

    N=len(A)
    M=len(B)
    L=N+M-1
    if min(N,M)<=50:
        if N<M:
            N,M=M,N
            A,B=B,A

        C=[0]*L
        for i in range(N):
            for j in range(M):
                C[i+j]+=A[i]*B[j]
                C[i+j]%=Mod

        return C

    H=L.bit_length()
    K=1<<H

    A=A+[0]*(K-N)
    B=B+[0]*(K-M)

    NTT(A)
    NTT(B)

    for i in range(K):
        A[i]=A[i]*B[i]%Mod

    Inverse_NTT(A)
    return A[:L]
#==================================================
from heapq import heapify,heappop,heappush

S=input()
N=len(S)

chi=[0]*26
for a in S:
    chi[ord(a)-ord("a")]+=1

Mod=998244353
Fact=[1]*(N+1)
Fact_inv=[1]*(N+1)
for i in range(1,N+1):
    Fact[i]=i*Fact[i-1]%Mod
    Fact_inv[i]=pow(Fact[i],Mod-2,Mod)

Q=[(chi[c],Fact_inv[:chi[c]+1]) for c in range(26)]
heapify(Q)

while len(Q)>=2:
    a,A=heappop(Q)
    b,B=heappop(Q)
    heappush(Q,(a+b,Convolution_Mod(A,B)))

_,A=heappop(Q)
X=0
for d,a in enumerate(A):
    if d>=1:
        X+=Fact[d]*a
        X%=Mod

print(X)