mod=10**9+7
s=input()
n=len(s)
a=[ord(x)-97 for x in s]
pow2=[1]
for i in range(n):
	pow2.append(pow2[-1]*2%mod)
ans=0
last=[0]*26
for i,x in enumerate(a):
	ans+=(pow2[i]-last[x])*pow2[n-i-1]
	ans%=mod
	last[x]+=pow2[i]
	last[x]%=mod
print(ans)