S = input().strip()
n = len(S)
if n < 3:
    print(0)
    exit()

# Initialize suffix array where suffix[i][c] is the count of character c from position i to end
suffix = [[0] * 26 for _ in range(n + 2)]  # suffix[n] and beyond are all zeros

for i in range(n-1, -1, -1):
    current_char = S[i]
    num = ord(current_char) - ord('A')
    # Copy the suffix counts from i+1 to i
    for k in range(26):
        suffix[i][k] = suffix[i+1][k]
    # Increment the current character count
    suffix[i][num] += 1

prefix_counts = [0] * 26
total = 0

for j in range(n):
    current_char = S[j]
    num = ord(current_char) - ord('A')
    a = prefix_counts[num]
    # Calculate the number of valid Y characters after position j
    if j + 1 < n:
        y_count = (n - j - 1) - suffix[j + 1][num]
    else:
        y_count = 0
    total += a * y_count
    # Update the prefix count for the current character
    prefix_counts[num] += 1

print(total)