import math
import sys
import time 
from collections import defaultdict
from collections import deque
cur_time = time.perf_counter()

INF = sys.maxsize
sys.setrecursionlimit( 10 ** 8 )

def alg_graph_scc( gs, rgs, n ):
    """
        gs: 隣接リスト
        rgs: 逆向き隣接リスト
    """
    order = []
    used = [0]*n
    group = [None]*n
    def dfs(s):
        used[s] = 1
        for t in gs[s]:
            if not used[t]:
                dfs(t)
        order.append(s)
    def rdfs(s, col):
        group[s] = col
        used[s] = 1
        for t in rgs[s]:
            if not used[t]:
                rdfs(t, col)
    for i in range(n):
        if not used[i]:
            dfs(i)
    used = [0]*n
    label = 0
    for s in reversed(order):
        if not used[s]:
            rdfs(s, label)
            label += 1
    return label, group


N, M = [ int(i) for i in input().split() ]
LR = [ [ int(i) for i in input().split() ] for _ in range( N ) ]
def solve():

    LRT = []
    for l, r in LR:
        LRT.append( ( M - 1 - r, M - 1 - l ) )

    gs = [[] for _ in range(2*N)]
    for i in range(N):
        l0, r0 = LR[i]
        for j in range(N):
            if i != j:
                l1, r1 = LRT[j]
                if not ( r0 < l1 or r1 < l0 ): # conflict
                    gs[i].append( j )
                    gs[N+i].append( N+j )
                l1, r1 = LR[j]
                if not( r0 < l1 or r1 < l0 ): # conflict
                    gs[i].append( N+j )
                    gs[N+i].append( j )

    label, group = alg_graph_scc( gs, gs, 2*N )
    for i in range(N):
        if group[i] == group[i+N]:
            print( 'NO' )
            return
    print( 'YES' )

solve()