import sys
sys.setrecursionlimit(10**7)
class DirectedGraph():
    def __init__(self, N):
        self.N = N
        self.G = [[] for i in range(N)]
        self.rG = [[] for i in range(N)]
        self.order = []
        self.group = [-1] * N
        self.label = 0

    def add_edge(self, u, v):
        self.G[u].append(v)
        self.rG[v].append(u)

    def dfs(self, s, used):
        used[s] = 1
        for u in self.G[s]:
            if used[u]:
                continue
            self.dfs(u, used)
        self.order.append(s)
        
    def rdfs(self, s, num, used):
        self.group[s] = num
        used[s] = 1
        for u in self.rG[s]:
            if used[u]:
                continue
            self.rdfs(u, num, used)

    def scc(self):
        used = [0] * self.N
        for i in range(self.N):
            if used[i]:
                continue
            self.dfs(i, used)
        used = [0] * self.N
        for s in reversed(self.order):
            if used[s]:
                continue
            self.rdfs(s, self.label, used)
            self.label += 1
        return self.label, self.group

    def construct(self):
        nG = [set() for _ in range(self.label)]
        mem = [[] for i in range(self.label)]
        for s in range(self.N):
            now = self.group[s]
            for u in self.G[s]:
                if now == self.group[u]:
                    continue
                nG[now].add(self.group[u])
            mem[now].append(s)
        return nG, mem


class TwoSAT():
    def __init__(self, N):
        self.G = DirectedGraph(2 * N)
        
    def add(self, x1, x2, f1, f2):
        if f1 == True and f2 == True:
            # ￢x1∪￢x2
            # (x1⇒￢x2)∩(x2⇒￢x1)
            self.G.add_edge(x1, x2 + N)
            self.G.add_edge(x2, x1 + N)
            
        if f1 == True and f2 == False:
            # ￢x1∪x2
            # (x1⇒x2)∩(￢x2⇒￢x1)
            self.G.add_edge(x1, x2)
            self.G.add_edge(x2 + N, x1 + N)
        
        if f1 == False and f2 == True:
            # x1∪￢x2
            # (￢x1⇒￢x2)∩(x2⇒x1)
            self.G.add_edge(x1 + N, x2 + N)
            self.G.add_edge(x2, x1)
            
        if f1 == False and f2 == False:
            # x1∪x2
            # (￢x1⇒x2)∩(￢x2⇒x1)
            self.G.add_edge(x1 + N, x2)
            self.G.add_edge(x2 + N, x1)
            
    def check(self):
        _, group = self.G.scc()
        for i in range(N):
            if group[i] == group[i + N]:
                return False
        return True
        

N, M = map(int, input().split())
L, R = [0] * N, [0] * N
cnt = 0
for i in range(N):
    L[i], R[i] = map(int, input().split())
    cnt += R[i] - L[i] + 1
    
if cnt > M:
    print("NO")
    exit()
    
def check(L1, R1, L2, R2):
    if R1 < L2 or R2 < L1:
        return True
    return False
    
TS = TwoSAT(N)
for i in range(N):
    for j in range(i + 1, N):
        if not check(L[i], R[i], L[j], R[j]):
            TS.add(i, j, True, True)
        if not check(L[i], R[i], M - 1 - R[j], M - 1 - L[j]):
            TS.add(i, j, True, False)
        if not check(M - 1 - R[i], M - 1 - L[i], L[j], R[j]):
            TS.add(i, j, False, True)
        if not check(M - 1 - R[i], M - 1 - L[i], M - 1 - R[j], M - 1 - L[j]):
            TS.add(i, j, False, False)
            
print("YES") if TS.check() else print("NO")