import sys
input = sys.stdin.buffer.readline
sys.setrecursionlimit(10 ** 7)


def main():
    N, M = map(int, input().split())
    TP = tuple(tuple(map(int, input().split())) for _ in range(M))
    now = 0
    time = 0
    for t, p in TP:
        move = abs(p - now)
        T = t - time
        if move > T:
            return False
        now = p
        time = t
    return True


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