Python: print the longest word in a sentence that contains the letter "a" or "A"

If there is no word contains "a" or "A" in a sentence, print -1.

Here is my code, I can print the words if they contain "a" or "A", but if not I can’t manage to print -1 out.

Where should I change?

def newsentence ():
    letters = set('aA')
    new_ls = [word for word in sentence if letters & set(word)]
    return new_ls

def findlongest ():
    if 'a' or 'A' in sentence: 
        longest = max(newsentence(), key=len)
    else:
        longest== -1
    return(longest)
    
sentence = list(input().split())
print(findlongest())

>Solution :

The newsentence will return an empty array if there is no a or A. Please change the code to below. It should work. As @Tomer said, you also need to change == to = as well

def newsentence ():
    letters = set('aA')
    new_ls = [word for word in sentence if letters & set(word)]
    return new_ls

def findlongest ():
    if 'a' or 'A' in sentence: 
        if newsentence():
            longest = max(newsentence(), key=len)
        else:
            longest = -1
    return(longest)

sentence = list(input().split())
print(findlongest())