S = list(input())

n = len(S)
DP = [[0 for _ in range(26)] for _ in range(n + 1)]
ans = 0
for i in range(n):
    idx = ord(S[i]) - ord('A')
    for j in range(26):
        if j == idx:
            DP[i + 1][j] = DP[i][j] + 1
        else:
            DP[i + 1][j] = DP[i][j]
    for j in range(26):
        if j == idx:
            continue
        ans += DP[i][j] * (DP[i][j] - 1) // 2
print(ans)