Once the boy named Richard received the cat as a gift. Of course, he immediately started to think up how to name him. Three his friends offered their variants: strings a, b and c of equal lengths n. Richard notes the distance between strings s1 and s2 as a number of positions in which the characters in these strings differ. For example, , . Richard wants to please his friends and name the cat such the name s that is minimal.
The first line contains one integer n (1 ≤ n ≤ 200000) — the length of the strings.
Then three strings a, b и c of the same length n follow — the names offered by Richard's friends. The strings consist of the lowercase Latin letters.
Output the only string of the length n, consisting of the lowercase Latin letters — the name for the cat. If there are many possible names satisfying the condition, output any of them.