B"Kuznecov likes art, poetry, and music. And strings consisting of lowercase English letters. Recently, Kuznecov has found two strings, a and b , of lengths n and m respectively. They consist of lowercase English letters and no character is contained in both strings. Let another string c be initially empty. Kuznecov can do the following two types of operations: But, he can not do more than k operations of the same type in a row. He must perform operations until either a or b becomes empty. What is the lexicographically smallest possible value of c after he finishes? A string x is lexicographically smaller than a string y if and only if one of the following holds: There are several test cases in the input data. The first line contains a single integer t ( 1 <= q t <= q 100 ) -- the number of test cases. This is followed by the test cases description. The first line of each test case contains three integers n , m , and k ( 1 <= q n,m,k <= q 100 ) -- parameters from the statement. The second line of each test case contains the string a of length n . The third line of each test case contains the string b of length m . The strings contain only lowercase English letters. It is guaranteed that no symbol appears in a and b simultaneously. In each test case, output a single string c -- the answer to the problem. In the first test case, it is optimal to take two 'a's from the string a and add them to the string c . Then it is forbidden to take more characters from a , hence one character 'b' from the string b has to be taken. Following that logic, we end up with c being 'aabaabaa' when string a is emptied. In the second test case it is optimal to take as many 'a's from string a as possible, then take as many 'b's as possible from string b . In the end, we take two 'c's from the string"...