B'A boy named Vasya wants to play an old Russian solitaire called "Accordion". In this solitaire, the player must observe the following rules: Vasya has already shuffled the cards and put them on the table, help him understand whether completing this solitaire is possible or not. The first input line contains a single integer n (1 xe2 x80 x89 xe2 x89 xa4 xe2 x80 x89n xe2 x80 x89 xe2 x89 xa4 xe2 x80 x8952) -- the number of cards in Vasya 's deck. The next line contains n space-separated strings c1, xe2 x80 x89c2, xe2 x80 x89..., xe2 x80 x89cn, where string ci describes the i-th card on the table. Each string ci consists of exactly two characters, the first one represents the card 's value, the second one represents its suit. Cards on the table are numbered from left to right. A card 's value is specified by one of these characters: "2", "3", "4", "5", "6", "7", "8", "9", "T", "J", "Q", "K", "A". A card 's suit is specified by one of these characters: "S", "D", "H", "C". It is not guaranteed that the deck has all possible cards. Also, the cards in Vasya 's deck can repeat. On a single line print the answer to the problem: string "YES" (without the quotes) if completing the solitaire is possible, string "NO" (without the quotes) otherwise. In the first sample you can act like that: In the second sample there is no way to complete the solitaire.'...