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()[::-1]  # Reverse the string for easier access
        ptr += 1
        s_list.append(s)
    
    mask0 = [0] * (N + 1)  # 1-based indexing
    mask1 = [0] * (N + 1)
    
    for m in range(M):
        s_reversed = s_list[m]
        for i in range(1, N + 1):
            if i - 1 >= len(s_reversed):
                c = '0'  # Assuming input strings are correctly length N, but handle just in case
            else:
                c = s_reversed[i - 1]
            if c == '0':
                mask0[i] |= (1 << m)
            else:
                mask1[i] |= (1 << m)
    
    found = False
    for i in range(1, N + 1):
        for j in range(i + 1, N + 1):
            if mask0[i] == mask0[j] and mask1[i] == mask1[j]:
                found = True
                break
        if found:
            break
    
    print("No" if found else "Yes")

if __name__ == "__main__":
    main()