n, m = map(int, input().split())
LR = [list(map(int, input().split())) for _ in range(n)]

LR.sort(key=lambda x: (-(x[1] - x[0]), x[0]))
DP = [0 for _ in range(m)]
for i in range(n):
    l, r = LR[i]
    flag = True
    for j in range(l, r + 1):
        if DP[j]:
            flag = False
            break
    if flag:
        for j in range(l, r + 1):
            DP[j] = 1
        continue
    l, r = m - 1 - r, m - 1 - l
    flag = True
    for j in range(l, r + 1):
        if DP[j]:
            flag = False
            break
    if flag:
        for j in range(l, r + 1):
            DP[j] = 1
        continue
    else:
        print("NO")
        exit()
print("YES")