S = input()
n = len(S)

cnt = [0] * 26
ans = 0

for i, s in enumerate(S):
    p = ord(s) - 65
    ans += cnt[p] * (n - 1 - i)
    cnt[p] += 1

for c in cnt:
    ans -= c * (c - 1) * (c - 2) // 6

print(ans)