A string is called a special if all the characters of the alphabets(uppercase or lowercase) appear in it at least once.

You are given a string consisting of lowercase and uppercase Latin letters. Check whether this string is special. We say that the string contains a letter of the Latin alphabet if this letter occurs in the string in uppercase or lowercase.

Input

The first line contains a single integer n (1 ≤ n ≤ 100) — the number of characters in the string.

The second line contains the string. The string consists only of uppercase and lowercase Latin letters.

Output

Output "YES", if the string is special and "NO" otherwise.