test = int(input())
for t in range(test):
	n , k = map(int,input().split())
	s = input()
	lastone = -1
	count = 0
 
	for i in range(n):
		if int(s[i])==1:
			if lastone>=max(0,i-k) and lastone<=i-1:
				continue
 
			else:
				count+=1
			lastone = i
		else:
			continue
	print(count)
 
 
 
				dGVzdCA9IGludChpbnB1dCgpKQpmb3IgdCBpbiByYW5nZSh0ZXN0KToKCW4gLCBrID0gbWFwKGludCxpbnB1dCgpLnNwbGl0KCkpCglzID0gaW5wdXQoKQoJbGFzdG9uZSA9IC0xCgljb3VudCA9IDAKCQoJZm9yIGkgaW4gcmFuZ2Uobik6CgkJaWYgaW50KHNbaV0pPT0xOgoJCQlpZiBsYXN0b25lPj1tYXgoMCxpLWspIGFuZCBsYXN0b25lPD1pLTE6CgkJCQljb250aW51ZQoJCQkJCgkJCWVsc2U6CgkJCQljb3VudCs9MQoJCQlsYXN0b25lID0gaQoJCWVsc2U6CgkJCWNvbnRpbnVlCglwcmludChjb3VudCkKCQkJCQoJCQkKCQk=