func_code_string: #include <bits/stdc++.h>   using namespace std;   const long long N = 1e+6 + 5;   long long big = 1e+18 + 3;   long long mod = 1e+9 + 7;   long long freq[26] = {0}, vis[N];   long long maxv = -1;   long long sz = 0;   void dfs(string &s, vector<vector<long long>> &gr, long long ind) {     vis[ind] = 1;     sz++;     freq[s[ind] - (long long) a ]++;     for (auto it : gr[ind])       if (!vis[it]) dfs(s, gr, it);   }   signed main() {     ios_base::sync_with_stdio(0);     cin.tie(0);     cout.tie(0);     long long t;     cin >> t;     while (t--) {       long long n;       long long k;       cin >> n >> k;       string s;       for (long long i = 0; i <= n; i++) vis[i] = 0;       vector<vector<long long>> gr(n + 1);       long long moves = 0;       cin >> s;       for (long long i = 0; i <= n - 1; i++) {         if (i + k < n) gr[i].push_back(i + k), gr[i + k].push_back(i);         if (i - k >= 0) gr[i].push_back(i - k), gr[i - k].push_back(i);         gr[i].push_back(n - i - 1);         gr[n - i - 1].push_back(i);       }       for (long long i = 0; i <= n - 1; i++) {         if (vis[i]) continue;         dfs(s, gr, i);         for (long long x = 0; x <= 25; x++) maxv = max(maxv, freq[x]);         moves += (sz - maxv);         for (long long x = 0; x <= 25; x++) freq[x] = 0;         maxv = -1;         sz = 0;       }       cout << moves <<   n ;     }   }   