N, W = map(int, input().split())
segments = []

for i in range(N):
    L, R = map(int, input().split())
    segments.append([R, L, i])
    segments.append([W - 1 - L, W - 1 - R, i])
segments.sort()
x = -1
used = [0] * N
for R, L, i in segments:
    if not used[i] and L > x:
        used[i] = 1
        x = R

print("YES" if used.count(0) == 0 else "NO")