Problem Description

Given a string containing some letters of the English alphabet, find all the missing letters from the complete alphabet (a-z). The comparison should be case-insensitive, and the result should be returned in lowercase alphabetical order.

Input Format

A single string containing letters (both uppercase and lowercase) and possibly other characters.

Output Format

A string containing all missing letters from the English alphabet in lowercase, sorted alphabetically.

Constraints

• 1 ≤ string length ≤ 1000

• String may contain letters, numbers, and special characters

• Only consider English alphabet letters (a-z, A-Z)

• Output should be lowercase and sorted

Sample Input/Output

abcdeFGhij

klmnopqrstuvwxyz

Explanation

The input contains letters: a,b,c,d,e,f,g,h,i,j (case-insensitive). Missing letters from the complete alphabet are: k,l,m,n,o,p,q,r,s,t,u,v,w,x,y,z