s=list(map(lambda x:ord(x)-97,list(input())))
b=[0]*26;ans=0;n=len(s);mod=10**9+7
f=[0]*26
for i in range(n):
    c=0;d=0
    for j in range(26):
        d+=f[j]
        if s[i]!=j:
            c+=b[j]
    ans+=c+1+d;ans%=mod;d+=c+1
    c+=1+b[s[i]]
    b[s[i]]+=c;b[s[i]]%=mod;f[s[i]]+=d;f[s[i]]%=mod
print(ans)