S = input()
N = len(S)
mod = 10**9+7

res = 0
num = [0]*26
sm = 0
pw = [0]*(N+1)
pw[0] = 1
for i in range(1,N+1):
    pw[i] = (pw[i-1]*2)%mod
for i in range(N):
    res += ((sm-num[ord(S[i])-97]+1)*pw[N-i-1])%mod
    res %= mod
    num[ord(S[i])-97] += pw[i]
    num[ord(S[i])-97] %= mod
    sm += pw[i]
    sm %= mod
print(res)