from itertools import permutations

D = list(map(int, input().split()))

for l in permutations(D):
    for i in range(5):
        sub_l = [l[i], l[i+1], l[i+2]]
        
        if l[i+1] in [min(sub_l), max(sub_l)] and l[i] < l[i+2] and 3 == len(set(sub_l)):
            continue
        else:
            break
    else:
        print('YES')
        break
else:
    print('NO')