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


def solve(n, m, lr):
    lr.sort(key=lambda x: min(x[0], m - 1 - x[1]))
    used = [False] * m
    for i in range(n):
        if all(not used[j] for j in range(lr[i][0], lr[i][1] + 1)):
            for j in range(lr[i][0], lr[i][1] + 1):
                used[j] = True
        elif all(not used[j] for j in range(m - 1 - lr[i][1], m - 1 - lr[i][0] + 1)):
            for j in range(m - 1 - lr[i][1], m - 1 - lr[i][0] + 1):
                used[j] = True
        else:
            return 0
    return 1


print("YES" if solve(n, m, lr) else "NO")