def longest_substring_without_110(s):
    max_length = 0
    current_length = 0
    last_index = -1

    for i, c in enumerate(s):
        if c == '1' and (i > 0 and s[i - 1] == '1') or c == '0' and (i > 1 and s[i - 2] == '0'):
            if i - last_index > max_length:
                max_length = i - last_index
            current_length = 0
            last_index = i
        else:
            current_length += 1

    return max_length + current_length

s = input("请输入一个01串：")
print("不包含110的最长子串长度为：", longest_substring_without_110(s))