#swap S=list(input()) S.sort() i=0 k=1 l=1 while i<len(S): if S[i]==S[i+1]: k*=2 j=2 while i<len(S) and S[i]==S[i+1]: j+=1 k*=j i+=1 i+=1 l*=i l*=i print(l//k)