#include<iostream>
#include<algorithm>
const int MAX = 251;
using namespace std;
int a[MAX];
int k;
char ch;
int main()
{
	int i = 0;
    while((ch = getchar()) != '\n')
	a[i++] = ch - '0';	
	int l = i;
    cin >> k;
    sort(a,a + l);
    for(i = 0;i < l - k;i++)
    cout << a[i]; 
    return 0;
}```