p, g = 998244353, 3
invg = pow(g, p-2, p)
W = [pow(g, (p - 1) >> i, p) for i in range(24)]
iW = [pow(invg, (p - 1) >> i, p) for i in range(24)]
 
def fft(k, f):
    for l in range(k)[::-1]:
        d = 1 << l
        u = 1
        for i in range(d):
            for j in range(i, 1 << k, 2*d):
                f[j], f[j+d] = (f[j] + f[j+d]) % p, u * (f[j] - f[j+d]) % p
            u = u * W[l+1] % p
 
def ifft(k, f):
    for l in range(k):
        d = 1 << l
        u = 1
        for i in range(d):
            for j in range(i, 1 << k, 2*d):
                f[j+d] *= u
                f[j], f[j+d] = (f[j] + f[j+d]) % p, (f[j] - f[j+d]) % p
            u = u * iW[l+1] % p
 
def convolve(a, b):
    n0, n1 = len(a), len(b)
    k = (max(n0, n1) - 1).bit_length() + 1
    n = 1 << k
    a = a + [0] * (n-n0)
    b = b + [0] * (n-n1)
    fft(k, a), fft(k, b)
    for i in range(n):
        a[i] = a[i] * b[i] % p
    ifft(k, a)
    invn = pow(n, p - 2, p)
    return [a[i] * invn % p for i in range(n0 + n1 - 1)]

import heapq

s=input()
n=len(s)
mod=998244353
cnt=[0]*26
for i in s:
  cnt[ord(i)-97]+=1
dp=[0]*(n+1)
dp[0]=1
A=[1]
f=[1]
finv=[1]
tmp=1
hq=[]
for i in range(1,n+1):
  tmp*=i
  tmp%=mod
  f.append(tmp)
  finv.append(pow(tmp,mod-2,mod))
for i in range(26):
  b=[1]
  for j in range(1,cnt[i]+1):
    b.append(finv[j])
  heapq.heappush(hq,(cnt[i]+1,b))
#print(a)
while len(hq)>1:
  sizea,a=heapq.heappop(hq)
  sizeb,b=heapq.heappop(hq)
  heapq.heappush(hq,(sizea+sizeb-1,convolve(a, b)))

a=hq[0][1]
ans=0
for i in range(1,n+1):
  ans+=a[i]*f[i]
  ans%=mod
print(ans)