S = list(input())
S = [ord(s) - ord("A") for s in S]
cnt = [0] * 26
ans = 0
for s in S:
    for i in range(26):
        if i == s:
            continue
        ans += cnt[i] * (cnt[i] - 1)//2
    cnt[s] += 1
    
print(ans)