N, M = map(int, input().split())
X = [0] * (M + 1)
for _ in range(N):
    l, r = map(int, input().split())
    X[l] += 1
    X[r + 1] -= 1
    X[M - r - 1] += 1
    X[M - l] -= 1
Y = [0] * M
for i in range(M):
    Y[i] = X[i] + Y[i - 1]
    if Y[i] > 2:
        print("NO")
        exit()
print("YES")