n, m = map(int, input().split())
blocks = [ tuple(map(int, input().split())) for _ in range(n)]
blocks = sorted(blocks, key=lambda x: x[1])

pink_block = [True for _ in range(m)]
def update(l, r):
    if all(pink_block[l:r+1]):
        pink_block[l:r+1] = [False]*(r-l+1)
        return True
    return False

for l, r in blocks:
    if not update(l, r):
        l, r = m - r - 1, m - l - 1
        if not update(l, r):
            print('NO'); exit()
print('YES')