CF1132A.Regular Bracket Sequence

普及/提高-

通过率：0%

AC君温馨提醒

该题目为【codeforces】题库的题目，您提交的代码将被提交至codeforces进行远程评测，并由ACGO抓取测评结果后进行展示。由于远程测评的测评机由其他平台提供，我们无法保证该服务的稳定性，若提交后无反应，请等待一段时间后再进行重试。

题目描述

A string is called bracket sequence if it does not contain any characters other than "(" and ")". A bracket sequence is called regular if it it is possible to obtain correct arithmetic expression by inserting characters "+" and "1" into this sequence. For example, "", "(())" and "()()" are regular bracket sequences; "))" and ")((" are bracket sequences (but not regular ones), and "(a)" and "(1)+(1)" are not bracket sequences at all.

You have a number of strings; each string is a bracket sequence of length $2$ . So, overall you have $cnt_1$ strings "((", $cnt_2$ strings "()", $cnt_3$ strings ")(" and $cnt_4$ strings "))". You want to write all these strings in some order, one after another; after that, you will get a long bracket sequence of length $2(cnt_1 + cnt_2 + cnt_3 + cnt_4)$ . You wonder: is it possible to choose some order of the strings you have such that you will get a regular bracket sequence? Note that you may not remove any characters or strings, and you may not add anything either.

输入格式

The input consists of four lines, $i$ -th of them contains one integer $cnt_i$ ( $0 \le cnt_i \le 10^9$ ).

输出格式

Print one integer: $1$ if it is possible to form a regular bracket sequence by choosing the correct order of the given strings, $0$ otherwise.

输入输出样例

输入#1
```
3
1
4
3
```
输出#1
```
1
```
输入#2
```
0
0
0
0
```
输出#2
```
1
```
输入#3
```
1
2
3
4
```
输出#3
```
0
```

说明/提示

In the first example it is possible to construct a string "(())()(()((()()()())))", which is a regular bracket sequence.

In the second example it is possible to construct a string "", which is a regular bracket sequence.

首页