import sys
input = sys.stdin.readline

S=input().strip()
mod=10**9+7

L=[]
for s in S:
    L.append(ord(s)-97)

ANS=0
ALIST=[0]*26
LEN=len(L)
SUM=0

for i in range(LEN):
    ANS=ANS+(1+SUM-ALIST[L[i]])*pow(2,LEN-i-1,mod)
    ANS%=mod

    #print(ANS)

    ALIST[L[i]],SUM=ALIST[L[i]]+(1+SUM),SUM+1+SUM
    ALIST[L[i]]%=mod
    SUM%=mod

    #print(ALIST)

print(ANS)