102822: [AtCoder]ABC282 C - String Delimiter

Problem Statement

You are given a string $S$ of length $N$ consisting of lowercase English letters, ,, and ". It is guaranteed that $S$ contains an even number of ".

Let $2K$ be the number of " in $S$. For each $i=1,2,\ldots,K$, the characters from the $(2i-1)$-th " through the $(2i)$-th " are said to be enclosed.

Your task is to replace each , in $S$ that is not an enclosed character with . and print the resulting string.

Constraints

• $N$ is an integer between $1$ and $2\times 10^5$, inclusive.
• $S$ is a string of length $N$ consisting of lowercase English letters, ,, and ".
• $S$ contains an even number of ".

Input

The input is given from Standard Input in the following format:

$N$
$S$

Output

Print the answer.

Sample Input 1

8
"a,b"c,d

Sample Output 1

"a,b"c.d

In $S$, "a,b" are enclosed characters, and c,d are not.

The , in $S$ that is not an enclosed character is the seventh character from the left in $S$, so replace that character with . to get the answer.

Sample Input 2

5
,,,,,

Sample Output 2

.....

Sample Input 3

20
a,"t,"c,"o,"d,"e,"r,

Sample Output 3

a."t,"c."o,"d."e,"r.

问题描述

你被给定一个长度为$N$的字符串$S$，它由小写字母、逗号和双引号组成。保证$S$包含偶数个双引号。

令$2K$为$S$中的双引号数量。对于每个$i=1,2,\ldots,K$，从第$(2i-1)$个双引号到第$(2i)$个双引号之间的字符被认为是< strong>被包围的。

你的任务是将$S$中每个< strong>不是被包围字符的逗号替换为点，并打印结果字符串。

约束

• $N$是一个介于$1$和$2\times 10^5$之间的整数，包括$1$和$2\times 10^5$。
• $S$是一个长度为$N$的字符串，由小写字母、逗号和双引号组成。
• $S$包含偶数个双引号。

输入

输入从标准输入中给出，格式如下：

$N$
$S$

输出

打印答案。

样例输入 1

8
"a,b"c,d

样例输出 1

"a,b"c.d

在$S$中，"a,b"是被包围的字符，而c,d不是。

$S$中不是被包围字符的逗号是$S$从左边数起的第七个字符，所以将该字符替换为.即可得到答案。

样例输入 2

5
,,,,,

样例输出 2

.....