#include<iostream>
#include<cstdio>
#include<cmath>
#include<iomanip>
#include<cstdlib>
#include<ctime>
#include<algorithm>
#include<cstring>
#include<string>
#include<sstream>
#include<vector>
#include<cassert>
#include<memory>
using namespace std;
char a[10005], b[10005];
int main()
{
int n, s, k;
while (scanf("%d%d", &n, &s)==2)
{
int temp = s, num = 0;
memset(b, 0, sizeof(b));
scanf("%s", a + 1);
for (int i = 1; i <= n; i++)
{
if (num>0 && a[i] != '0'&&b[1]>a[i] && s >= num)
{
s = s - num;
b[1] = a[i];
num = 1;
continue;
}
while (num>0 && s>0 && b[num]>a[i])
{
if (num == 1 && a[i] == '0')
break;
s = s - 1, num = num - 1;
}
num++;
b[num] = a[i];
}
for (int i = 1; i <= n - temp; i++)
cout<<b[i];
cout << endl;
}
}