import sys
readline = sys.stdin.readline
write = sys.stdout.write
def scc(N, G, RG):
    order = []
    used = [0]*N
    group = [None]*N
    def dfs(s):
        used[s] = 1
        for t in G[s]:
            if not used[t]:
                dfs(t)
        order.append(s)
    def rdfs(s, col):
        group[s] = col
        used[s] = 1
        for t in RG[s]:
            if not used[t]:
                rdfs(t, col)
    for i in range(N):
        if not used[i]:
            dfs(i)
    used = [0]*N
    label = 0
    order.reverse()
    for s in order:
        if not used[s]:
            rdfs(s, label)
            label += 1
    return label, group
def solve():
    N, M = map(int, readline().split())
    S = [tuple(map(int, readline().split())) for i in range(N)]

    G = [[] for i in range(2*N)]
    RG = [[] for i in range(2*N)]
    def add_edge(i, neg_i, j, neg_j):
        if neg_i:
            i0 = i+N; i1 = i
        else:
            i0 = i; i1 = i+N
        if neg_j:
            j0 = j+N; j1 = j
        else:
            j0 = j; j1 = j+N
        G[i1].append(j0); RG[j0].append(i1)
        G[j1].append(i0); RG[i0].append(j1)

    for i in range(N):
        li, ri = S[i]
        for j in range(i+1, N):
            lj, rj = S[j]
            if (li <= rj and lj <= ri):
                add_edge(i, 0, j, 0)
                add_edge(i, 1, j, 1)
            if (li <= M-1-lj and M-1-rj <= ri):
                add_edge(i, 0, j, 1)
                add_edge(i, 1, j, 0)
    label, group = scc(2*N, G, RG)

    ok = 1
    for i in range(N):
        if group[i] == group[i+N]:
            ok = 0
            break
    if ok:
        write("YES\n")
    else:
        write("NO\n")
solve()