#D1874. The minimal unique substring
The minimal unique substring
The minimal unique substring
Let s be some string consisting of symbols "0" or "1". Let's call a string t a substring of string s, if there exists such number 1 ≤ l ≤ |s| - |t| + 1 that t = s_l s_{l+1} … s_{l + |t| - 1}. Let's call a substring t of string s unique, if there exist only one such l.
For example, let s = "1010111". A string t = "010" is an unique substring of s, because l = 2 is the only one suitable number. But, for example t = "10" isn't a unique substring of s, because l = 1 and l = 3 are suitable. And for example t ="00" at all isn't a substring of s, because there is no suitable l.
Today Vasya solved the following problem at the informatics lesson: given a string consisting of symbols "0" and "1", the task is to find the length of its minimal unique substring. He has written a solution to this problem and wants to test it. He is asking you to help him.
You are given 2 positive integers n and k, such that (n mod 2) = (k mod 2), where (x mod 2) is operation of taking remainder of x by dividing on 2. Find any string s consisting of n symbols "0" or "1", such that the length of its minimal unique substring is equal to k.
Input
The first line contains two integers n and k, separated by spaces (1 ≤ k ≤ n ≤ 100 000, (k mod 2) = (n mod 2)).
Output
Print a string s of length n, consisting of symbols "0" and "1". Minimal length of the unique substring of s should be equal to k. You can find any suitable string. It is guaranteed, that there exists at least one such string.
Examples
Input
4 4
Output
1111
Input
5 3
Output
01010
Input
7 3
Output
1011011
Note
In the first test, it's easy to see, that the only unique substring of string s = "1111" is all string s, which has length 4.
In the second test a string s = "01010" has minimal unique substring t ="101", which has length 3.
In the third test a string s = "1011011" has minimal unique substring t ="110", which has length 3.
inputFormat
Input
The first line contains two integers n and k, separated by spaces (1 ≤ k ≤ n ≤ 100 000, (k mod 2) = (n mod 2)).
outputFormat
Output
Print a string s of length n, consisting of symbols "0" and "1". Minimal length of the unique substring of s should be equal to k. You can find any suitable string. It is guaranteed, that there exists at least one such string.
Examples
Input
4 4
Output
1111
Input
5 3
Output
01010
Input
7 3
Output
1011011
Note
In the first test, it's easy to see, that the only unique substring of string s = "1111" is all string s, which has length 4.
In the second test a string s = "01010" has minimal unique substring t ="101", which has length 3.
In the third test a string s = "1011011" has minimal unique substring t ="110", which has length 3.
样例
4 4
1111