#pragma comment(linker, "/stack:16777216")
#include <string>
#include <vector>
#include <map>
#include <list>
#include <iterator>
#include <set>
#include <queue>
#include <iostream>
#include <sstream>
#include <stack>
#include <deque>
#include <cmath>
#include <memory.h>
#include <cstdlib>
#include <cstdio>
#include <cctype>
#include <algorithm>
#include <utility>

using namespace std;

#define FOR(i,a,b) for(int i = (a); i < (b); ++i)
#define RFOR(i,b,a) for(int i = (b) - 1; i >= (a); --i)
#define REP(i,N) FOR(i, 0, N)
#define RREP(i,N) RFOR(i, N, 0)
#define FILL(A,value) memset(A,value,sizeof(A))

#define ALL(V) V.begin(), V.end()
#define SZ(V) (int)V.size()
#define PB push_back
#define MP make_pair
#define Pi 3.14159265358979

typedef long long Int;
//typedef unsigned long long UINT;
typedef vector <int> VI;
typedef pair <int, int> PII;

const int INF = 1000000000;
const int MAX = 200000;
const int MAX2 = 1000000;
const int BASE = 1000000000;
const int CNT = 20;

#define MOD 1000000007

struct Test
{
    int n, k;
    string s;
    Test(){}
    int D[MAX];
    int solve()
    {
        // sum will be the current change
        // In D we will keep where are positions where we have to subtract 1 from the current change
        FILL(D, 0);
        int res = 0, sum = 0;
        FOR (i,0,n)
        {
            int d = (s[i] == 'R' ? 0 : 1);
            sum ^= D[i];
            d ^= sum;
            if (d == 0)
            {
                ++ res;
                sum ^= 1;
                D[min(n, i+k)] ^= 1;
            }
        }
        return res;
    }
    void writeTest()
    {
        cout << n << ' ' << k << endl;
        cout << s << endl;
    }
    void writeRes()
    {
        cout << solve() << endl;
    }
    void readTest()
    {
        cin >> n >> k;
        cin >> s;
    }
};


int main()
{
    int cnt;
    cin >> cnt;
    FOR (i,0,cnt)
    {
        Test t;
        t.readTest();
        t.writeRes();
    }



	return 0;
}