S=input()
N=len(S)
X=[[] for i in range(26)]
for i in range(N):
  X[ord(S[i])-ord('a')].append(i)
P=0
Q=0
mod=10**9+7
for i in range(26):
  Q=0
  for j in range(len(X[i])):
    if j:
      P=(P+Q*pow(2,N-1-X[i][j],mod))%mod
    Q=(Q+pow(2,X[i][j],mod))%mod
print((pow(2,N-1,mod)*N-P)%mod)