#include <bits/stdc++.h>   using namespace std;   long long dp[114514][16];   int N, M;   char s[114514];   long long res;   int main() {     scanf( %d%d , &N, &M);     scanf( %s , &s);     dp[0][2] = 1;     for (int(i) = 0; (i) < (N); (i)++)       for (int(b) = (1); (b) < (16); (b)++)         if (dp[i][b]) {           for (int(j) = 0; (j) < (M); (j)++) {             int nb = 0;             if (b % 2 == 1 && s[i - 1] == j +  a ) nb |= 1;             if (b % 2 == 1 && s[i] == j +  a ) nb |= 8;             if (b / 2 % 2 == 1 && s[i] == j +  a ) nb |= 2;             if (b / 2 % 2 == 1) nb |= 1;             if (b / 2 % 2 == 1 && i + 1 < N && s[i + 1] == j +  a ) nb |= 4;             if (b / 4 % 2 == 1) nb |= 8;             if (b / 4 % 2 == 1 && i + 1 < N && s[i + 1] == j +  a ) nb |= 4;             if (b >= 8 && s[i] == j +  a ) nb |= 8;             if (b / 2 % 2 == 1) nb |= 8;             dp[i + 1][nb] += dp[i][b];           }         }     for (int(i) = (8); (i) < (16); (i)++) res += dp[N][i];     cout << res - 1 + dp[N][1] + dp[N][4] + dp[N][5] << endl;   }   