S = input()
alpha_set = set(list(S))
A = [{s:0 for s in alpha_set} 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]
    for key in A[i]:
        if s == key:
            continue
        ans += A[i][key]*(A[i][key]-1)//2
        # print(s,key, A[i][key]*(A[i][key]-1)//2)
print(ans)