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;
using ll = long long;
const int inf = 1e9 + 7;
const ll longinf = 1LL << 60;
const ll mod = 1e9 + 7;
int main() {
  int n, m;
  cin >> n >> m;
  string s;
  cin >> s;
  s += '#';
  ll sum = (m - 1) * n;
  ll ans = 0;
  char prepre = '#', pre = '#';
  int cnt = 1;
  for (int i = (int)(0); i < (int)(n); ++i) {
    if (prepre == s[i])
      ++cnt;
    else
      cnt = 1;
    prepre = pre;
    pre = s[i];
    if (prepre == s[i]) continue;
    ans += sum;
    ans -= cnt;
  }
  cout << ans + 1 << endl;
  return 0;
}
