Alex has a string S of length N consisting of lowercase alphabets. He wants to find lexicographically smallest string X of length N that can be formed using the following operation.

In one operation, he can select any one character among the at most first K characters of string S, remove it from string S and append it to string X. He can apply this operation as many times as he wants.

Help Alex find the string X.

Input format

• The first line consists of a string of length N
• The second line consists of an integer K.

Output format

• Print the lexicographically minimum string that can be formed using the above operation.

Constraints

• \(1 \le N \le 10^{5}\)
• \(1 \le K \le N\)