#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<algorithm>
#include<string>
#include<iostream>
#include<sstream>
#include<set>
#include<map>
#include<queue>
#include<bitset>
#include<vector>
#define SZ(X) ((int)(X).size())
#define ALL(X) (X).begin(), (X).end()
#define REP(I, N) for (int I = 0; I < (N); ++I)
#define REPP(I, A, B) for (int I = (A); I < (B); ++I)
#define RI(X) scanf("%d", &(X))
#define RII(X, Y) scanf("%d%d", &(X), &(Y))
#define RIII(X, Y, Z) scanf("%d%d%d", &(X), &(Y), &(Z))
#define DRI(X) int (X); scanf("%d", &X)
#define DRII(X, Y) int X, Y; scanf("%d%d", &X, &Y)
#define DRIII(X, Y, Z) int X, Y, Z; scanf("%d%d%d", &X, &Y, &Z)
#define RS(X) scanf("%s", (X))
#define CASET int ___T, case_n = 1; scanf("%d ", &___T); while (___T-- > 0)
#define MP make_pair
#define PB push_back
#define MS0(X) memset((X), 0, sizeof((X)))
#define MS1(X) memset((X), -1, sizeof((X)))
#define LEN(X) strlen(X)
#define PII pair<int,int>
#define VI vector<int>
#define VPII vector<pair<int,int> >
#define PLL pair<long long,long long>
#define VPLL vector<pair<long long,long long> >
#define F first
#define S second
typedef long long LL;
using namespace std;
const int MOD = 1e9+7;
const int SIZE = 1e6+10;
char s[SIZE];
int dp[101][101][51];
template <class T>
void maa(T& x,T y){
    if(x<y)x=y;
}
template <class T>
void mii(T& x,T y){
    if(x>y)x=y;
}
int main(){
    CASET{
        DRII(n,m);
        m/=2;
        RS(s);
        VI d;
        REP(i,n)if(s[i]=='2')d.PB(n-i);
        reverse(ALL(d));
        REP(i,SZ(d)+1)REP(j,n+1)REP(k,m+1)dp[i][j][k]=-1;
        dp[0][0][0]=0;
        REP(i,SZ(d)){
            REPP(j,1,n+1)REP(k,m+1)maa(dp[i][j][k],dp[i][j-1][k]);
            REP(k,m+1){
                REPP(k2,max(1,d[i]-(m-k)),min(n,d[i]+(m-k))+1){
                    if(k2>=3&&dp[i][k2-3][k]!=-1)maa(dp[i+1][k2][k+abs(d[i]-k2)],dp[i][k2-3][k]+1);
                    maa(dp[i+1][k2][k+abs(d[i]-k2)],dp[i][k2-1][k]);
                }
            }
        }
        int an=0;
        REP(i,n+1)
            REP(j,m+1)maa(an,dp[SZ(d)][i][j]);
        printf("%d\n",an);
    }
    return 0;
}