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

n,m=map(int,input().split())
L,R=[],[]
for _ in range(n):
    l,r=map(int,input().split())
    L.append(l)
    R.append(r)

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

for i in range(n):
    for j in range(i):
        l1,r1=L[i],R[i]
        l2,r2=L[j],R[j]
        if (l1<=l2 and l2<=r1) or (l2<=l1 and l1<=r2):
            G[i].append(j+n)
            G[j].append(i+n)
        l2,r2=m-R[j]-1,m-L[j]-1
        if (l1<=l2 and l2<=r1) or (l2<=l1 and l1<=r2):
            G[i].append(j)
            G[j+n].append(i+n)
        l1,r1=m-R[i]-1,m-L[i]-1
        if (l1<=l2 and l2<=r1) or (l2<=l1 and l1<=r2):
            G[i+n].append(j)
            G[j+n].append(i)
        l2,r2=L[j],R[j]
        if (l1<=l2 and l2<=r1) or (l2<=l1 and l1<=r2):
            G[i+n].append(j+n)
            G[j].append(i)

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