You are given a string S that consists of N lowercase letters of the Latin alphabet.
In one step, you can remove any letter in the string. You are required to determine the maximum lexicographic sentence of words you can leave so that all letters are different.
The lexicographical order on the set of all these finite words orders the words in the following manner:
Input format
Output format
For each test case, print the answer.
Constraints
1≤T≤101≤N≤105|S|=N
For the first string, the answer is "yc" because "yc" > "ybd", "yc" > "y", "yc" > "yd", "y" > "a", "y" > "b" and "y" > "c".
For the second string, the answer is "z" because strings "zz" and "zzz" have the same letters.