def main():
    Str = input()
    k = int(input())

    res = ['0']
    if k >= len(Str):
        print('0')
        return 

    # 遍历Str
    for val in Str:
        while k and res[-1] > val:
            res.pop()
            k -= 1
        res.append(val)

    # 完全排序后, k 还没用完
    if k:
        res = res[: len(res) - k]

    # 去前面的0    
    for i in range(len(res)):
        if res[i] != '0':
            res = ''.join(res[i:])
            break
    print(res)  

main()