from collections import defaultdict

dic = defaultdict(list)
S = list(input())
for i, s in enumerate(S, start=1):
    dic[s].append(i)
N = len(S)
ans = 0
for k, V in dic.items():
    n = len(V)
    for j, v in enumerate(V, start=1):
        if j > 1:
            ans += (j - 1) * (N - v - n + j)
print(ans)