def main():
    import sys
    input = sys.stdin.read().split()
    idx = 0
    N = int(input[idx])
    idx += 1
    M = int(input[idx])
    idx += 1
    strings = []
    for _ in range(M):
        strings.append(input[idx])
        idx += 1
    
    # Precompute the bitmasks for each position i (1-based)
    bitmasks = {}
    for i in range(1, N+1):
        pos = N - i  # 0-based index in the string
        mask = 0
        for k in range(M):
            if strings[k][pos] == '1':
                mask |= (1 << k)
        bitmasks[i] = mask
    
    # Check all pairs (i, j) with i < j
    for i in range(1, N):
        for j in range(i+1, N+1):
            if (bitmasks[i] ^ bitmasks[j]) == 0:
                print("No")
                return
    print("Yes")

if __name__ == "__main__":
    main()