from itertools import combinations

def is_cpctf_like(s):
    # s: 長さ5のリスト
    for i in range(5):
        for j in range(i + 1, 5):
            if i == j:
                continue
            same = (s[i] == s[j])
            ij = {i + 1, j + 1}
            valid = same == (ij == {1, 3})
            if not valid:
                return False
    return True

def count_cpctf_like_subsequences(S):
    N = len(S)
    count = 0
    for indices in combinations(range(N), 5):
        s = [S[i] for i in indices]
        if is_cpctf_like(s):
            count += 1
    return count