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>
using namespace std;
const long long N = 100010;
long long ans, k, n;
int main() {
  long long i, j, tmp = 1;
  scanf("%lld%lld", &n, &k);
  char ch = getchar(), s1 = '-', s2 = '-';
  while (ch < 'a' || ch > 'z') ch = getchar();
  s1 = ch;
  ans = n * (k - 1);
  for (i = 1; i < n; i++) {
    ch = getchar();
    tmp = (ch == s2) ? tmp + 1 : 0;
    if (ch != s1) ans += n * (k - 1) - tmp - 1;
    s2 = s1, s1 = ch;
  }
  cout << ans << endl;
  return ~~(0 - 0);
}
