#include <bits/stdc++.h>
using namespace std;

#define endl '\n'
#ifdef LOCAL
    #include "debug.h"    
#else
    #define print(...)
    #define printt(...)
#endif

#define int long long

void run(){
    
    int n, k; string s;
    cin >> n >> k >> s;

    vector<int>a;
    int cnt = 0;
    for( int i = 0 ; i < n ; i++ ) {
        if(s[i] == '1') {
            cnt++;
        }else{
            if(cnt > 0)a.push_back(cnt);
            cnt = 0;
        }
    }
    if(cnt > 0)a.push_back(cnt);
    
    sort(a.rbegin(), a.rend());
    print(a);
    int ans = 0;
    for( int i = 0 ; i < min((int)a.size(), k+1) ; i++ )
        ans += a[i];
    
    cout << ans << endl;
}

int32_t main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);

    int t = 1;
    cin >> t;
    
    while( t --> 0 ) 
        run();
    
    return 0;
}