import sys

input=sys.stdin.readline

N,M=map(int,input().split())
eye=[tuple(map(int,input().split())) for i in range(M)]
eye.append((0,0))
eye.sort()
check=True
for i in range(1,M+1):
    pt,pp=eye[i-1]
    t,p=eye[i]
    if abs(pp-p)>t-pt:
        check=False

print("Yes" if check else "No")