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.
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*.
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()

  	  	 	 			 			 	  								