MOD = 10 ** 9 + 7
S = input()
ans = 0
n = len(S)
bi = [1] * (n + 1)
for i in range(n):
    bi[i + 1] = bi[i] * 2 % MOD
cnt = [0] * 26
add = 1
for i, s in enumerate(S):
    s = ord(s) - 97
    tmp = 1
    for j in range(26):
        if j != s:
            tmp += cnt[j]
            tmp %= MOD
    ans += tmp * bi[n - i - 1]
    ans %= MOD
    cnt[s] += add
    cnt[s] %= MOD
    add *= 2
    add %= MOD
print(ans)