import sys
input = lambda: sys.stdin.readline().rstrip()

ALPHABET = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ'

def main():
    # 入力
    S = input()
    N = len(S)
    # 計算・出力
    prev = {s:0 for s in ALPHABET}
    next = {s:0 for s in ALPHABET}
    for s in S:
        next[s] += 1
    ans = 0
    for i, s in enumerate(S):
        next[s] -= 1
        ans += prev[s] * (N-i-1 - next[s])
        prev[s] += 1
    print(ans)

if __name__ == "__main__":
    main()