# 2文字目を固定すると、(自分より前の同じ文字の個数)*(自分より後ろの自分以外の文字の数) # というわけで、現時点の自分と同じ文字のカウントがあれば良さそう S = input() n = len(S) alphabet = "ABCDEFGHIJKLMNOPQRSTUVWXYZ" # assert len(alphabet) == len(set(list(alphabet))) == 26 ci_map = dict() for i, c in enumerate(alphabet): ci_map[c] = i # 自分より前の同じ文字の個数 counter = [0] * 26 same_before = [0] * n for i, c in enumerate(S): j = ci_map[c] same_before[i] = counter[j] counter[j] += 1 res = 0 for i in range(n): before = same_before[i] c = S[i] j = ci_map[c] after = n - 1 - i - (counter[j] - before - 1) res += before * after print(res)