You are given a string S of length N. Among its subsequences, count the ones such that all characters are different, modulo 10^9+7. Two subsequences are considered different if their characters come from different positions in the string, even if they are the same as strings.  Here, a subsequence of a string is a concatenation of **one or more** characters from the string without changing the order.
n,s=open(0);a=1
for t in set(s):a*=-~s.count(t)
print(~-a%(10**9+7))
n,s=open(0);a=1
for x in range(26):a*=-~s.count(chr(97+x))
print(~-a%(10**9+7))