def nand(x, y):
    if x == y == 1: return 0
    else: return 1

N = 6
A = list(map(int, input().split()))
B = A
ANS = 'NO'

for i in range(N):
    for j in range(N):
        if A[i] == B[j]:
            A[i] = j
            break

for p in range(1<<N):
    P = []
    for i in range(N):
        P.append((p>>i)&1)
    if nand(nand(nand(P[A[0]], P[A[1]]), P[A[2]]), nand(nand(P[A[3]], P[A[4]]), P[A[5]])): ANS = 'YES'

print(ANS)