alphabetlist=['a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v','w','x','y','z']

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

def solve(alp):
    dp=[0]*N
    tmp=0
    if S[0]==alp:
        dp[0]=1
        tmp=1
    else:
        tmp=0

    for i in range(1,N):
        if S[i]==alp:
            dp[i]=2*dp[i-1]+(pow(2,i,mod)-tmp)
            dp[i]%=mod
            tmp+=pow(2,i,mod)
            tmp%=mod
        else:
            dp[i]=2*dp[i-1]
            dp[i]%=mod
    return dp[-1]

ans=0
for a in alphabetlist:
    ans+=solve(a)
    ans%=mod

print(ans)