#include <iostream>
#include <bits/c++io.h>
using namespace std;
int t; long long n,k;
char c[(int)1e7];
int main()
{
scanf("%d",&t);
while(t--){
scanf("%I64d%I64d",&n,&k);
scanf("%s",&c);
long long st=0,en=0,cnt=0,curr=0,ans=0;
while(k==0 && en<n){
while(c[en]=='1' && en<n) {cnt=0; en++;}
while(c[en]=='0' && en<n) {cnt++; en++;}
ans+=cnt;
}
if(k==0) {printf("%I64d\n",ans); continue;}
while(en<n){
curr+=(c[en]=='1');
while(curr==k){
cnt++;
en++;
if(c[en]=='1'||en==n) {st++;curr=0;en=st-1;break;}
}
en++;
}
printf("%I64d\n" ,cnt);
}
return 0;
}
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