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;
int n, m, o, re = 0;
long long res = 0;
char a[1000010], b[1000010];
bool chk[1000010];
int main() {
  int i, j, k, l;
  long long ll = 0, rr = 9223372036854775807LL, mid;
  scanf("%d %d", &n, &m);
  scanf("%s", a);
  k = 0;
  for (i = 0; i < n; i++) {
    if (i == 0 || a[i] == a[i - 1])
      k = 0;
    else if (a[i] == a[i - 2])
      k++;
    else
      k = 1;
    if (a[i] != a[i + 1]) res += (long long)(n) * (m - 1);
    res -= k;
  }
  printf("%I64d", res);
  return 0;
}
