from collections import defaultdict

s = input()

ans = 0
t = 0
dd = defaultdict(int)
for c in s:
    k = 0
    dd[c] += 1
    if 2 <= dd[c]:
        t += dd[c] - 1
        k = (dd[c] * (dd[c] - 1)) // 2
    ans += t - k


print(ans)