문제링크 : 크게만들기
n,m=map(int, input().split())
num=list(map(int, input().strip()))
result=[]
count=0
for i in range(n):
while count<m and result:
if result[len(result)-1]<num[i]:
result.pop()
count += 1
else:
break
result.append(num[i])
for i in range(n-m):
print(result[i],end="")