题目描述
Problem Statement
For an integer x not less than 0, we define g_1(x), g_2(x), f(x) as follows:
- g_1(x)= the integer obtained by rearranging the digits in the decimal notation of x in descending order
- g_2(x)= the integer obtained by rearranging the digits in the decimal notation of x in ascending order
- f(x)=g_1(x)-g_2(x)
For example, we have g_1(314)=431, g_2(3021)=123, f(271)=721-127=594. Note that the leading zeros are ignored.
Given integers N, K, find a_K in the sequence defined by a_0=N, a_{i+1}=f(a_i)\ $(i\geq 0)$.
Input
Input is given from Standard Input in the following format:
N K
Output
Print a_K.
Constraints
- $0 \leq N \leq 10^9$
- $0 \leq K \leq 10^5$
- All values in input are integers.
Sample Input 1
314 2
Sample Output 1
693
We have:
- a_0=314
- a_1=f(314)=431-134=297
- a_2=f(297)=972-279=693
Sample Input 2
1000000000 100
Sample Output 2
0
We have:
- a_0=1000000000
- a_1=f(1000000000)=1000000000-1=999999999
- a_2=f(999999999)=999999999-999999999=0
- a_3=f(0)=0-0=0
- $\vdots$
Sample Input 3
6174 100000
Sample Output 3
6174
输入格式
见题面 Input 部分
输出格式
见题面 Output 部分
样例输入
314 2
样例输出
693