#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
static bool cmp(const char a,const char b);
int main()
{
	string n;
	char fir,temp;
	int k,firpl;
	int zeros = 0;
	cin >> n;
	cin >> k;
	sort(n.begin(), n.end(),cmp);
	for (int i=0;i<n.size();i++)
	{
		if (n[i] == '0')
			continue;
		else
		{
			fir = n[i];
			firpl = i;
			break;
		}
	}
	if (n[0] == '0')
	{
		temp = n[0];
		n[0] = n[firpl];
		n[firpl] = temp;
	}
	for (int i = 0; i < k; i++)
	{
		n.pop_back();
	}
	cout << n<<endl;
}
static bool cmp(const char a,const char b)
{
	return string(1,a)+string(1,b)>string(1,b)+string(1,a);
}