def is_kaimatsu(a,b,c):
    if a==b or b==c or c==a:
        return False
    return (a>b<c) or (a<b>c)

from itertools import permutations
D=list(map(int,input().split()))
N=7

F=0
for t in permutations(D):
    G=1
    for i in range(5):
        if not (is_kaimatsu(t[i],t[i+1],t[i+2]) and t[i]<t[i+2]):
            G=0
    F|=G

print("YES" if F else "NO")