n, m = map(int, input().split())
lrs = [tuple(map(int, input().split())) for _ in range(n)]

lrs.sort(key=lambda lr: min(lr[0], m - 1 - lr[1]))
used = [False] * m
for l, r in lrs:
    if all(not used[i] for i in range(l, r + 1)):
        for i in range(l, r + 1):
            used[i] = True
    elif all(not used[i] for i in range(m - 1 - r, m - 1 - l + 1)):
        for i in range(m - 1 - r, m - 1 - l + 1):
            used[i] = True
    else:
        print("NO")
        exit()

print("YES")