def beautifulBinaryString(b):
    l = list(b)
    steps = 0
    
    for i in range(len(b)-2):
        if "".join(l[i : i + 3]) == '010':
            steps += 1
            if i + 3 < len(b) and l[i + 3] == '1':
                l[i + 2] = '1'
            else:
                l[i + 1] = '0'
    
    return steps