You are given a string S of length n with each character being one of the first m lowercase English letters. 

Calculate how many different strings T of length n composed from the first m lowercase English letters exist such that the length of LCS (longest common subsequence) between S and T is n - 1.

Recall that LCS of two strings S and T is the longest string C such that C both in S and T as a subsequence.

Input

The first line contains two numbers n and m denoting the length of string S and number of first English lowercase characters forming the character set for strings (1 ≤ n ≤ 100 000, 2 ≤ m ≤ 26).

The second line contains string S.

Output

Print the only line containing the answer.

Examples

Input

3 3
aaa


Output

6


Input

3 3
aab


Output

11


Input

1 2
a


Output

1


Input

10 9
abacadefgh


Output

789

Note

For the first sample, the 6 possible strings T are: aab, aac, aba, aca, baa, caa. 

For the second sample, the 11 possible strings T are: aaa, aac, aba, abb, abc, aca, acb, baa, bab, caa, cab.

For the third sample, the only possible string T is b.
def main():
    n, m = map(int, input().split())
    s = input()
    k = sum(s[i] != s[i - 1] for i in range(1, n)) + 1
    x = i = 0
    while i < n - 1:
        if s[i] != s[i + 1]:
            j = i
            while i + 2 < n and s[i] == s[i + 2]:
                i += 1
            j = (i - j) + 2
            x += j * (j - 1) // 2
        i += 1
    ans = k * (m * n - n) - x
    print(ans)
main()
