C++ :

#include<iostream>
#include<cstdio>
using namespace std;
int main()
{
	string n;
	int s;
	cin>>n;
	cin>>s;
	int l=n.size();
	for(int i=1;i<=s;++i)
	{
		for(int j=0;j<l-1;++j)
		
			if(n[j]>n[j+1])
			{
				for(int k=j;k<l-1;k++)
				n[k]=n[k+1];
				break;
			}
			
		l--;;
	}
	
	bool f=0;
	for(int i=0;i<=l-1;i++)
	{
		if(n[i]!='0')
		f=true;
		if(f)cout<<n[i];
	}
}

Pascal :

var
  i,j,n:longint;
  s:ansistring;
begin
  readln(s);
  readln(n);
	if length(s)=n then begin write(0);exit; end;
  for i:=1 to n do
  begin
	  if length(s)=1 then break;
	  j:=1;
	  while (s[j+1]>=s[j])and(j<length(s)) do inc(j);
	  delete(s,j,1);
	  while (s[1]='0')and(length(s)>1) do delete(s,1,1);
  end;
  write(s);
end.