S = input()
A = [ord(C) - 97 for C in S]
POW2 = [1]
for i in range(len(S)):
	POW2.append(POW2[-1] * 2 % (10 ** 9 + 7))
ANS = 0
LAST = [0] * 26
for I, X in enumerate(A):
	ANS += (POW2[I] - LAST[X]) * POW2[len(S) - I - 1]
	ANS %= (10 ** 9 + 7)
	LAST[X] += POW2[I]
	LAST[X] %= (10 ** 9 + 7)
print(ANS)