S = [ord(s)-65 for s in input()]
M = 26
dp = [[0]*M for _ in range(3)]
ct = [0]*26
s2 = 0
for a in S:
    dp[2][a] += (s2-dp[1][a])
    dp[1][a] += ct[a]
    dp[0][a] += 1
    s2 += ct[a]
    ct[a] += 1

print(sum(dp[2]))