import sys
read=sys.stdin.readline
sys.setrecursionlimit(10**9)

def SCC(G,N):
    rG=[[] for _ in range(N)]
    P=[]
    seen=[0]*N
    for v in range(N):
        for nv in G[v]:
            rG[nv].append(v)
            
    def dfs(G,v):
        seen[v]=1
        for nv in G[v]:
            if not seen[nv]:
                dfs(G,nv)
        P.append(v)
    
    def rdfs(G,v,C):
        seen[v]=1
        group[v]=C
        for nv in G[v]:
            if not seen[nv]:
                rdfs(G,nv,C)
    for v in range(N):
        if not seen[v]:
            dfs(G,v)
    
    seen=[0]*N
    group=[-1]*N
    C=0
    for v in P[::-1]:
        if not seen[v]:
            rdfs(rG,v,C)
            C+=1
            
    Size=max(group)+1
    return group,Size

def intersect(l1,r1,l2,r2):
    if r1<l2 or r2<l1:
        return False
    return True

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

G=[[] for _ in range(2*n)]

for i in range(n):
    for j in range(i):
        c=0
        l1,r1=blocks[i]
        l2,r2=blocks[j]
        if intersect(l1,r1,l2,r2):
            G[i].append(j+n)
            G[j].append(i+n)
            c+=1
        l2,r2=m-r2-1,m-l2-1
        if intersect(l1,r1,l2,r2):
            G[i].append(j)
            G[j+n].append(i+n)
            c+=1
        l1,r1=m-r1-1,m-l1-1
        if intersect(l1,r1,l2,r2):
            G[i+n].append(j)
            G[j+n].append(i)
            c+=1
        l2,r2=m-r2-1,m-l2-1
        if intersect(l1,r1,l2,r2):
            G[i+n].append(j+n)
            G[j].append(i)
            c+=1
        if c==4:
            print('NO')
            exit()

group,_=SCC(G,2*n)
for i in range(n):
    if group[i]==group[i+n]:
        print('NO')
        exit()
print('YES')