import sys

sys.setrecursionlimit(10 ** 6)
def MI(): return map(int, sys.stdin.readline().split())

def main():
    n,m=MI()
    b=[0]*(m+1)
    for _ in range(n):
        l,r=MI()
        b[l-1]+=1
        b[r]-=1
    for i in range(m):
        b[i+1]+=b[i]
        if b[i+1]>2:
            print("NO")
            break
    else:
        print("YES")

main()