Once Tigger was jumping merrily through the forest and inventing a new game. In general, as you know, Tigra is very fond of various games, and most often they are mobile ones. But on that day, clouds were gradually gathering over the forest, and therefore all Tigers' thoughts were about a quiet and calm game.

And here Tigra remembered a very funny and entertaining game that he and Rabbit played in their distant childhood. Although its rules were not simple, the game took a lot of time and brought a lot of pleasure.

A couple of minutes later, Tiger met Eeyore and asked him to play. The donkey agreed and then the Tiger told him the rules of the game: the players take turns attributing one of the letters of the English alphabet they know to the line, but at the same time, two identical combinations of two consecutive characters should not be formed in the line. The one who cannot make a move loses.

Eeyore was very interested in this game and wanted to beat the Tiger. First, he wants to come up with the longest string that can be obtained in the course of this game. Help him with this!

Input

One number k (1 ≤ k ≤ 26) - the number of the first letters of the English alphabet known to the heroes.

Output

Print a string consisting of k the first lowercase letters of the English alphabet - the answer to the problem.