#include <iostream>

using namespace std;

int ktra(string n, int k){
	if (n.size() <= k) return 0;
	else return 1;
}

int dem(string s){
	int res = 0;
	for (int i = s.size()-1; i>= 0; i--){
		if (s[i]!='0') return res;
		res++;
	}
}

string del(string s, int k){
	return s.substr(0,k)+s.substr(k+1,s.size()-1-k);
}

int main(){
	int k;
	int demthaotac=0;
	string n;
	cin >> n;
	cin >> k;
	int size = n.size();
	if (!ktra(n,k)) cout << (size-1);
	else{
		int i = size-1;
		while (dem(n)<k){
		//	cout << dem(n) << endl;
			if (n[i]!='0') {
				n = del(n, i);
				//cout << "n: " << n << endl;
				demthaotac++;
			}
			i--;
			if (!ktra(n,k)){
				cout << (size-1);
				return 0;
			}
		}
		cout << demthaotac;
	}
	return 0;
}