s = list(map(lambda c: ord(c)-65, input()))
n = len(s)
dp = [[[0, 0, 0] for _ in range(26)] for _ in range(n+1)]
for i in range(n):
  c = s[i]
  for j in range(26):
    for k in range(3):
      dp[i+1][j][k] += dp[i][j][k]
    dp[i+1][c][2] += dp[i][j][1] * (c != j)
  dp[i+1][c][0] += 1
  dp[i+1][c][1] += dp[i][c][0]
ans = 0
for i in range(26):
  ans += dp[n][i][2]
print(ans)