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.
#include <bits/stdc++.h>
long long n, m, t, ans = 1;
char s[100005];
int main() {
  scanf("%lld%lld%s", &n, &m, s + 2), s[0] = s[1] = '#';
  for (int i = 1; i <= n; ++i) {
    if (s[i + 1] == s[i - 1])
      ++t;
    else
      t = 0;
    if (s[i + 1] != s[i]) ans += n * (m - 1) - t - 1;
  }
  return 0 & printf("%lld", ans);
}
