func_code_string: #include <bits/stdc++.h>   using namespace std;   const int N = 1e5 + 5;   int n, m, same;   string s;   int main() {     cin >> n >> m >> s;     long long ans = 1LL * n * (m - 1);     for (int i = 1; i < n; i++) {       if (s[i] == s[i - 2]) {         same++;       } else {         same = 0;       }       if (s[i] != s[i - 1]) {         ans += 1LL * n * (m - 1) - same - 1;       }     }     cout << ans << endl;     return 0;   }   