def read_data():
    N, M = map(int, input().split())
    LR = []
    for n in range(N):
        L, R = map(int, input().split())
        LR.append((L, R))
    return N, M, LR

def solve(N, M, LR):
    imos = [0] * (M + 1)
    for L, R in LR:
        imos[L] += 1
        imos[R + 1] -= 1
        imos[M - R - 1] += 1
        imos[M - L] -= 1
    cum = 0
    for v in imos:
        cum += v
        if cum > 2:
            return False
    return True

N, M, LR = read_data()
if solve(N, M, LR):
    print('YES')
else:
    print('NO')