#include <bits/stdc++.h>   using namespace std;   int main() {     ios::sync_with_stdio(false);     int q;     cin >> q;     string s;     int n, k;     string r =   , g =   , b =   ;     vector<string> v;     for (int i = 0; i < 1500; i++) {       r +=  RGB ;       b +=  BRG ;       g +=  GBR ;     }     for (int m = 0; m < q; m++) {       v.clear();       cin >> n >> k;       cin >> s;       string d;       for (int i = 0; i < s.length(); i++) {         d = s.substr(i, k);         if (d.length() == k) v.push_back(d);       }       long long minn = 1e9;       for (vector<string>::iterator it = v.begin(); it != v.end(); it++) {         int cntr = 0;         int cntb = 0;         int cntg = 0;         string s1 = (*it);         for (int i = 0; i < s1.length(); i++) {           if (s1[i] != r[i]) {             cntr++;           }           if (s1[i] != b[i]) {             cntb++;           }           if (s1[i] != g[i]) {             cntg++;           }         }         int mio = min(cntr, min(cntb, cntg));         if (mio < minn) minn = mio;       }       cout << minn << endl;     }     return 0;   }   