s = input()
n = len(s)
dp = [[0] * 26 for _ in range(n)]

# print(ord("a"), ord("A"))

dp[0][ord(s[0])-65] += 1
dp[1] = dp[0].copy()
dp[1][ord(s[1])-65] += 1

ans = 0
for i in range(2, n):
    dp[i] = dp[i-1].copy()
    dp[i][ord(s[i])-65] += 1
    dpi = dp[i]
    ordi = ord(s[i])-65
    for j in range(26):
        if dpi[j] >= 2 and ordi != j:
            ans += dpi[j]*(dpi[j]-1)//2
# print(dp)
print(ans)