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.
import java.io.*;
import java.util.*;
import java.math.*;

public class p578d {
    public static void main(String[] args) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        InputReader in = new InputReader(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        long n = in.nextLong();
        long m = in.nextLong();
        String str = in.next();
        char[] x = str.toCharArray();
        int[] y = new int[(int)n];
        long res = n * (m - 1);
        for (int i = 1; i < n; i++) {
            if (x[i] != x[i - 1]) {
                res += (long)i * (m - 1);
            }
        }
        for (int i = 0; i < n - 1; i++) {
            if (x[i] != x[i + 1]) {
                res += (n - (long)i - 1) * (m - 1);
            }
        }
        for (int i = 0; i < n; i++) {
            if (i < 2 || x[i] != x[i - 2]) {
                y[i] = 1;
            } else {
                y[i] = y[i - 2] + 1;
            }
            if (i > 0) {
                int len = Math.min(2 * y[i], 2 * y[i - 1] + 1);
                if (x[i] != x[i - 1] && len >= 2) {
                    res -= len - 1;
                }
            }
        }
        out.println(res);
        out.close();
    }

    static class Pair implements Comparable<Pair> {
        int x;
        int y;

        public Pair(int x, int y) {
            super();
            this.x = x;
            this.y = y;
        }

        @Override
        public int compareTo(Pair p) {
            return x < p.x ? -1 : x > p.x ? 1 : 0;
        }
    }

    static class InputReader {
        public BufferedReader reader;
        public StringTokenizer tokenizer;

        public InputReader(InputStream stream) {
            reader = new BufferedReader(new InputStreamReader(stream), 32768);
            tokenizer = null;
        }

        public String next() {
            while (tokenizer == null || !tokenizer.hasMoreTokens()) {
                try {
                    tokenizer = new StringTokenizer(reader.readLine());
                } catch (IOException e) {
                    throw new RuntimeException(e);
                }
            }
            return tokenizer.nextToken();
        }

        public int nextInt() {
            return Integer.parseInt(next());
        }

        public long nextLong() {
            return Long.parseLong(next());
        }

        public double nextDouble() {
            return Double.parseDouble(next());
        }

        public String nextLine() {
            try {
                return reader.readLine();
            } catch (IOException e) {
                e.printStackTrace();
            }
            return null;
        }

        public boolean hasMoreElements() {
            while (tokenizer == null || !tokenizer.hasMoreElements()) {
                String s;
                try {
                    s = reader.readLine();
                } catch (IOException e) {
                    return false;
                }
                tokenizer = new StringTokenizer(s);
            }
            return tokenizer.hasMoreElements();
        }
    }
}