def nand(x, y):
    return (not x) or (not y)

def eval(p):
    return nand(nand(nand(p[0], p[1]), p[2]), nand(nand(p[3], p[4]), p[5]))

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

for b in range(1 << 6):
    x = [False] * 6
    for i in range(6):
        if (b & (1 << i)) != 0:
            x[i] = True
    ok = True
    for i in range(6):
        for j in range(i):
            if a[i] == a[j] and x[i] != x[j]:
                ok = False
    if ok and eval(x):
        print("YES")
        exit()
print("NO")