N, M = map(int, input().split())
A = [list(map(int, input().split())) for _ in range(M)]

S = 0
ans = 0
for i in range(M):
    T,P = A[i]
    if i != 0:
        T = T - A[i-1][0]
    if S-T <= P <= S+T:
        S = P
        ans += 1
    else:
        break

print('Yes' if M == ans else 'No')