you give stre s length n integer k you tasked find long subsequence repeat k time string sA subsequence string derive string delete character change order remain charactersA subsequence seq repeat k time string s seq k subsequence s seq k represent string construct concatenate seq k timesFor example bba repeat 2 time stre bababcba string bbabba construct concatenate bba 2 time subsequence stre bababcbareturn long subsequence repeat k time string s if multiple subsequence find return lexicographically large if subsequence return string Example 1input s letsleetcode k 2output letexplanation there long subsequence repeat 2 time let etelet lexicographically large oneexample 2input s bb k 2output bExplanation the long subsequence repeat 2 time bExample 3input s ab k 2Output Explanation there subsequence repeat 2 time empty string return Constraintsn slength2 n k 20002 n k 8s consists lowercase english letter