from bitarray import bitarray

n = int(input())
m = int(input())
st = [bitarray(input()) for _ in [0] * m]

for i in range(n):
	a = bitarray([True] * n)
	b = bitarray([False] * n)
	for bits in st:
		if(bits[i]):
			a &= bits
		else:
			b |= bits
	for j in range(n):
		if(i == j):
			continue
		if(a[j] and not(b[j])):
			print("No")
			exit(0)
print("Yes")