import sys

readline = sys.stdin.buffer.readline
readall = sys.stdin.read
ns = lambda: readline().rstrip()
ni = lambda: int(readline().rstrip())
nm = lambda: map(int, readline().split())
nl = lambda: list(map(int, readline().split()))
prn = lambda x: print(*x, sep='\n')

def modinv(x, mod):
    a, b = x, mod
    u, v = 1, 0
    while b:
        t = a // b
        a -= t * b; a, b = b, a
        u -= t * v; u, v = v, u
    return u % mod

mod = 10**9 + 7
n = 2 * 10 ** 5 + 10
pos = [1] * n
neg = [1] * n
for i in range(1, n):
    pos[i] = pos[i-1] * 2 % mod
neg[-1] = modinv(pos[-1], mod)
for j in range(n-2, -1, -1):
    neg[j] = neg[j+1] * 2 % mod


def solve():
    sig = 26
    s = [x - 97 for x in list(ns())]
    n = len(s)
    cur = 0
    g = [list() for _ in range(sig)]
    for i in range(n):
        g[s[i]].append(i)
    for x in range(sig):
        m = len(g[x])
        h = [neg[y] for y in g[x]]
        for j in range(m-2, -1, -1):
            h[j] += h[j+1]
        for i in range(m-1):
            # print(pow(2, n-1, mod) * pos[g[x][i]] * h[i+1] % mod)
            cur = (cur + pos[g[x][i]] * h[i+1]) % mod
    print((n - cur) * pow(2, n-1, mod) % mod)


    return

solve()