def main():
    import sys
    input = sys.stdin.read().split()
    ptr = 0
    N = int(input[ptr])
    ptr += 1
    M = int(input[ptr])
    ptr += 1
    s_list = []
    for _ in range(M):
        s = input[ptr].strip()
        ptr += 1
        s_list.append(s)
    
    mask = [0] * (N + 1)  # mask[1..N]
    
    for m in range(M):
        s = s_list[m]
        s_rev = s[::-1]  # Reverse the string to access rightmost as first character
        for i in range(1, N + 1):
            if s_rev[i-1] == '1':
                mask[i] |= 1 << m
    
    valid = True
    for i in range(1, N+1):
        for j in range(i+1, N+1):
            if (mask[i] ^ mask[j]) == 0:
                valid = False
                print("No")
                return
    print("Yes")

if __name__ == "__main__":
    main()