S = input()
n = len(S)
cnt = {}
for s in S:
    cnt[s] = cnt.get(s, 0) + 1

def comb(n, r):
    ret = 1
    for i in range(n, n - r, -1):
        ret *= i
    for i in range(2, r + 1):
        ret //= i
    return ret

ans = 0
for v in cnt.values():
    ans += comb(n, v)
    n -= v
print(ans - 1)