n = int(input())
m = int(input())
strings = [input().strip()[::-1] for _ in range(m)]

mask0 = [0] * n  # mask0[i] is the mask for bit i being 0
mask1 = [0] * n  # mask1[i] is the mask for bit i being 1

for idx, s in enumerate(strings):
    for i in range(n):
        if s[i] == '0':
            mask0[i] |= 1 << idx
        else:
            mask1[i] |= 1 << idx

ok = True
for i in range(n):
    for j in range(i + 1, n):
        if (mask0[i] & mask1[j]) != 0 or (mask1[i] & mask0[j]) != 0:
            continue
        else:
            ok = False
            break
    if not ok:
        break

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