from collections import Counter

def are_happy(b):
    for i in range(len(b)):
        happy = False
        if i > 0:
            if b[i-1] == b[i]:
                happy = True
        if i < len(b) - 1:
            if b[i+1] == b[i]:
                happy = True
        if not happy:
            return False
    return True
        

def happyLadybugs(b):
    c = Counter(b)
    if c['_'] < 1:
        if are_happy(b):
            return 'YES'
        else:
            return 'NO'
    
    for key, count in c.most_common()[::-1]:
        if count == 1 and key != '_':
            return 'NO'
        if count > 1:
            return 'YES'
    return 'YES'