from collections import *
from itertools import *
from functools import *
from heapq import *
import sys,math
input = sys.stdin.readline

S = list(input())[:-1]
S = [ord(s)-ord('A') for s in S]
N = len(S)
ans = 0
dp = [0]*26
for i in range(N):
    s = S[i]
    dp[s] += 1
    for j in range(26):
        if j==s:
            continue
        ans += dp[j]*(dp[j]-1)//2
print(ans)