S=[ord(s)-97 for s in input()]
M=26
mod=10**9+7
dp0=[0]*M
dp1=[0]*M
for s in S:
    prev0=dp0[:]
    prev1=dp1[:]
    dp0[s]+=1
    dp1[s]+=1
    for t in range(26):
        dp0[s]+=prev0[t]
        dp1[s]+=prev1[t]
        if s!=t:
            dp1[s]+=prev0[t]
    dp0[s]%=mod
    dp1[s]%=mod
ans=sum(dp1)%mod
print(ans)