from collections import Counter
S = input()
A = [{s:0 for s in set(list(S))} for _ in range(len(S)+1)]
for i, s in enumerate(S):
    i += 1
    for key in A[i]:
        A[i][key] += A[i-1][key] 
    A[i][s] += 1 
# print(A[-1])
ans = 0
for i in  range(len(S)):
    s = S[i]
    if A[i][s] >= 1:
        ans +=  A[i][s]*(len(S) - 1 - i )
print(ans)