import sys
readline = sys.stdin.readline

def crossing(M, b0, b1):
    l0, r0 = b0
    l1, r1 = b1
    t0 = l1 <= r0 and l0 <= r1
    l0, r0 = M - 1 - r0, M - 1 - l0
    t1 = l1 <= r0 and l0 <= r1
    if t0 and t1:
        return "NG"
    if t0 or t1:
        return True
    return False

def dfs(x, G, visited, finished, parity):
    visited[x] = True
    for y in G[x]:
        if visited[y]:
            if not finished[y] and parity == 1:
                return True
            continue
        dfs(y, G, visited, finished, 1 - parity)
    finished[x] = True
    return False

def main():
    N, M = map(int, readline().split())
    blocks = [tuple(map(int, readline().split())) for _ in range(N)]
    G = [[] for _ in range(N)]
    for i in range(N):
        for j in range(i + 1, N):
            t = crossing(M, blocks[i], blocks[j])
            if t == "NG":
                print("NO")
                return
            if t:
                G[i].append(j)
                G[j].append(i)

    visited = [False] * N
    finished = [False] * N
    for x in range(N):
        if finished[x]:
            continue
        if dfs(x, G, visited, finished, 1):
            print('NO')
            return
    print('YES')

if __name__ == "__main__":
    main()