import sys
import logging
import math
input = sys.stdin.readline
logger = logging.getLogger(__name__)


def read():
    S = input().strip()
    return S,


def nC2(n):
    return n * (n-1) // 2


def solve(S):
    N = len(S)
    count = [[0 for j in range(26)] for i in range(N)]
    for i in range(N):
        s = ord(S[i]) - ord('A')
        for j in range(26):
            count[i][j] = count[i-1][j]
        count[i][s] += 1
    
    ans = 0
    for i in range(1, N):
        s = ord(S[i]) - ord('A')
        for j in range(26):
            if j == s:
                continue
            if count[i-1][j] >= 2:
                ans += nC2(count[i-1][j])
    return ans


if __name__ == "__main__":
    inputs = read()
    outputs = solve(*inputs)
    if outputs is not None:
        print("%s" % str(outputs))