import numpy as np

n = int(input())
m = int(input())
lis = [np.array([bool(int(c)) for c in input()]) for _ in [0] * m]

for i in range(n):
	a = np.array([True] * n)
	b = np.array([False] * n)
	for bits in lis:
		if(bits[i]):
			a &= bits
		else:
			b |= bits
	c = a & ~b
	c[i] &= False
	if c.any():
		print("No")
		exit(0)
print("Yes")