Find the difference between two collections. The difference means that either the character is present in one collection or it is present in other, but not in both. Return a sorted set with difference.
The collections can contain any character and can contain duplicates.
For instance:
A = [a,a,t,e,f,i,j]
B = [t,g,g,i,k,f]
difference = [a,e,g,j,k]
# return a sorted set with the difference
def diff(a, b):
    output = []
    for elem in a:
        if elem not in b:
            output.append(elem)
    for elem in b:
        if elem not in a:
            output.append(elem)
    return sorted(list(set(output)))
# return a sorted set with the difference
def diff(a, b):
    output = []
    for elem in a:
        if elem not in b:
            output.append(elem)
    for elem in b:
        if elem not in a:
            output.append(elem)
    return sorted(list(set(output)))