import sys
input = sys.stdin.readline

N,M=map(int,input().split())
X=[(0,0)]+[tuple(map(int,input().split())) for i in range(M)]
ANS=1
for i in range(1,M+1):
    if X[i][0]-X[i-1][0]<abs(X[i][1]-X[i-1][1]):
        ANS=0

if ANS:
    print("Yes")
else:
    print("No")