Who is longer?#2362
Once, Tigger was merrily jumping through the forest, inventing a new game. As you may know, Tigger loves all sorts of games, especially the active ones. However, that day clouds were gathering over the forest, and so all of Tigger's thoughts were about a quiet and calm game.
Suddenly, Tigger remembered a very funny and entertaining game he used to play with Rabbit in childhood. Its rules were not simple, but the game lasted a long time and was very enjoyable.
A few minutes later, Tigger met Eeyore and invited him to play. Eeyore agreed, and then Tigger explained the rules: players take turns appending one of the English alphabet letters they know to a string, but the string must not contain two identical combinations of two consecutive characters. The player who cannot make a move loses.
Eeyore was very interested in this game and wanted to beat Tigger. First, he wants to find the longest possible string that can be obtained during the game. Help him with this!
One number (1 \leq k \leq 26) — the number of the first letters of the English alphabet known to the characters.
Print a string consisting of the first lowercase letters of the English alphabet — the answer to the problem.
Example 1