import sys
read=sys.stdin.buffer.read
readline=sys.stdin.buffer.readline
readlines=sys.stdin.buffer.readlines

def scc(g):
    n=len(g)
    cmp=[0]*n
    ord=[-1]*n
    fin=[False]*n
    low=[0]*n
    visited=[]
    num=0
    k=0
    for x in range(n):
        if ord[x]!=-1:
            continue
        st=[~x, x]
        while st:
            v=st.pop()
            if v>=0:
                if ord[v]!=-1:
                    continue
                ord[v]=num
                low[v]=num
                num+=1
                visited.append(v)
                for w in g[v]:
                    if ord[w]==-1:
                        st.append(~w)
                        st.append(w)
            else:
                v=~v
                if fin[v]:
                    continue
                fin[v]=True
                for w in g[v]:
                    if ord[w]<ord[v]:
                        if ord[w]<low[v]:
                            low[v]=ord[w]
                    elif ord[w]<n:
                        if low[w]<low[v]:
                            low[v]=low[w]
                if ord[v]==low[v]:
                    while True:
                        w=visited.pop()
                        cmp[w]=k
                        ord[w]=n
                        if w==v:
                            break
                    k+=1
    cmp=[k-1-x for x in cmp]
    return (k, cmp)
n, m=map(int, readline().split())
lr=list(map(int, read().split()))
l=lr[::2]
r=lr[1::2]
g=[[] for _ in range(2*n)]
for i in range(n):
    l1, r1=l[i], r[i]
    for j in range(i):
        l2, r2=l[j], r[j]
        dame=0
        if not (r1<l2 or r2<l1):
            g[i].append(j+n)
            g[j].append(i+n)
            dame+=1
        if not (r1<m-1-r2 or m-1-l2<l1):
            g[i].append(j)
            g[j+n].append(i+n)
            dame+=1
        if dame==2:
            print("NO")
            exit()
        if not (m-1-l1<l2 or r2<m-1-r1):
            g[i+n].append(j+n)
            g[j].append(i)
        if not (m-1-l1<m-1-r2 or m-1-l2<m-1-r1):
            g[i+n].append(j)
            g[j+n].append(i)
k, cmp=scc(g)
for x in range(n):
    if cmp[x]==cmp[x+n]:
        print("NO")
        exit()
print("YES")