_, M = map(int, input().split())
c_pos = 0
c_time = 0
data = tuple(map(int, input().split()) for _ in range(M))
answer = 1
for t, p in data:
    d = abs(c_pos - p)
    lim = t - c_time
    if lim < d:
        answer ^= 1
        break
    c_pos = p
    c_time = t
print('Yes' if answer else 'No')