en2asc = lambda s: ord(s) - 97

S = input()
MOD = 10 ** 9 + 7
ct = [0] * 26
run = [0] * 26
p2 = 1
for s in S:
    i = en2asc(s)
    ct[i] += p2
    ct[i] %= MOD
    p2 *= 2
    p2 %= MOD

    run[i] *= 2
    run[i] += 1
    for j in range(26):
        if i == j:
            continue
        run[i] += run[j] + ct[j]
    run[i] %= MOD
print(sum(run) % MOD)