import numpy as np

N, M = map(int, input().split())
lst = [0] * (M + 1)
for i in range(N):
    l, r = map(int, input().split())
    lst[l] += 1
    lst[r + 1] -= 1

Acc = np.cumsum(lst[:-1])
flag = np.any(Acc + Acc[::-1] > 2)
print('NO' if flag else 'YES')