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];
	}
}

Python :

# coding=utf-8
a=list(map(lambda x: int(x), input().split()))[0]
s=[]
while a!=0:
    s.append(a%10)
    a = a // 10
s.reverse()
n=list(map(lambda x: int(x), input().split()))[0]
s1=s
for i in range(n):
    l=len(s)
    f=1
    for j in range(l-1):
        if s[j]>s[j+1]:
            s.remove(s[j])
            f=0
            break
        if f==1 and j==l-2:
            s.remove(s[l-1])
#print(s)
s2=[]
for i in s:
    s2.append(i)
for i in s:
    if i==0:
        #print(i)
        s2.remove(i)
    else:
        break

for i in s2:
    print (i,end='')