
#include <iostream>
#include <iomanip>
#include <vector>
#include <algorithm>
#include <numeric>
#include <functional>
#include <cmath>
#include <queue>
#include <stack>
#include <set>
#include <map>
#include <sstream>
#include <string>
#define repd(i,a,b) for (int i=(int)(a);i<(int)(b);i++)
#define rep(i,n) repd(i,0,n)
#define all(x) (x).begin(),(x).end()
#define mod 1000000007
#define inf 2000000007
#define mp make_pair
#define pb push_back
typedef long long ll;
using namespace std;
template <typename T>
inline void output(T a, int p) {
    if(p) cout << fixed << setprecision(p)  << a << "\n";
    else cout << a << "\n";
}
// end of template

int main() {
    cin.tie(0);
    ios::sync_with_stdio(0);
    // source code
    int N;
    string s;
    int D;
    cin >> N >> s >> D;
    
    vector<int> vis(N, 0);
    
    rep(i, N){
        if (s[i] == '0' && D > 0) {
            D--;
            s[i] = '1';
            vis[i] = 1;
        }
    }
    for (int i = N - 1; i >= 0; i--) {
        if (s[i] == '1' && D > 0 && vis[i] == 0) {
            D--;
            s[i] = '0';
        }
    }
    
    output(s, 0);
    return 0;
}