def left_join(phrases):
    list_phrases = list(phrases)
    
    for i,v in enumerate(list_phrases):
        list_phrases[i] = v.replace('right', 'left')
    
    return ",".join(list_phrases)

a609c327ca8de1c34aea8500ca1be9f3a775598c
<mask token>

def left_join(phrases):
    list_phrases = list(phrases)
    for i, v in enumerate(list_phrases):
        list_phrases[i] = v.replace('right', 'left')
    return ','.join(list_phrases)

def left_join(phrases):
    list_phrases = list(phrases)
    
    for i,v in enumerate(list_phrases):
        list_phrases[i] = v.replace('right', 'left')
    
    return ",".join(list_phrases)
