d = [0] * 26
ans = 0
s = input()
n = len(s)
for i in range(n):
    x = ord(s[i]) - 65
    ans += d[x] * (n - (i + 1))
    d[x] += 1
ans -= sum(x * (x - 1) * (x - 2) // 6 for x in d)
print(ans)