CF128B String

One day in the IT lesson Anna and Maria learned about the lexicographic order. String $ x $ is lexicographically less than string $ y $ , if either $ x $ is a prefix of $ y $ (and $ x≠y $ ), or there exists such $ i $ ( $ 1

The first line contains a non-empty string that only consists of small Latin letters ("a"-"z"), whose length does not exceed $ 10^{5} $ . The second line contains the only integer $ k $ ( $ 1

Print the string Anna and Maria need — the $ k $ -th (in the lexicographical order) substring of the given string. If the total number of substrings is less than $ k $ , print a string saying "No such line." (without the quotes).

In the second sample before string "bc" follow strings "a", "ab", "abc", "b".