line = 'Hello world!'

new_words = []

for word in line.split():
    new_word = ""
    
    fisrt = True
    for po in range(len(word)):
        
        if fisrt:
            fisrt = False
            new_word += word[po].lower()
            continue

        new_word += word[po].upper()

    new_words.append(new_word)
    
to_print = ""

for word in new_words:
    to_print += " " + word

print(' '.join(new_words))