import queue
import numpy as np

MOD=998244353

def convolve(f,g):
    fft=np.fft.rfft
    ifft=np.fft.irfft
    Lf=len(f)
    Lg=len(g)
    L=Lf+Lg-1
    fft_len=1<<L.bit_length()
    fl=f&(1<<15)-1
    gl=g&(1<<15)-1
    fh=f>>15
    gh=g>>15
    def conv(f,g):
        return ifft(fft(f,fft_len)*fft(g,fft_len))[:L]
    x=conv(fl,gl)%MOD
    y=conv(fl+fh,gl+gh)%MOD
    z=conv(fh,gh)%MOD
    a,b,c=map(lambda x : (x+.5).astype(np.int64) ,[x,y,z])
    return (a+((b-a-c)<<15)+(c<<30))%MOD

MAX=3*(10**5)+10
fac=[1]*MAX
ifac=[1]*MAX
for i in range(2,MAX):
    fac[i]=fac[i-1]*i%MOD
ifac[-1]=pow(fac[-1],MOD-2,MOD)
for i in range(MAX-2,0,-1):
    ifac[i]=(i+1)*ifac[i+1]%MOD

S=input()
cnt=[0]*27
for s in S:
    cnt[ord(s)-ord('a')]+=1
polys=queue.Queue()
for i in range(27):
    f=np.array([0]*(cnt[i]+1),np.int64)
    for j in range(cnt[i]+1):
        f[j]=ifac[j]
    polys.put(f)
for i in range(27-1):
    polys.put(convolve(polys.get(),polys.get()))

ans=0
poly=polys.get()
for i in range(1,len(poly)):
    ans=(ans+poly[i]*fac[i])%MOD
print(ans)