CF849A.Odds and Ends

Where do odds begin, and where do they end? Where does hope emerge, and will they ever break?

Given an integer sequence _a_1, _a_2, ..., a__n of length n. Decide whether it is possible to divide it into an odd number of non-empty subsegments, the each of which has an odd length and begins and ends with odd numbers.

A subsegment is a contiguous slice of the whole sequence. For example, {3, 4, 5} and {1} are subsegments of sequence {1, 2, 3, 4, 5, 6}, while {1, 2, 4} and {7} are not.

奇数从何开始，又在何处终结？希望于何时萌生，它们是否终将破灭？

给定一个长度为 $n$ 的整数序列 $a_1, a_2, ..., a_n$。请判断能否将其划分为奇数个非空子段，使得每个子段长度为奇数，且每个子段的首尾元素均为奇数。

子段（subsegment）是指整个序列的一个连续片段。例如，$\{3, 4, 5\}$ 和 $\{1\}$ 是序列 $\{1, 2, 3, 4, 5, 6\}$ 的子段，而 $\{1, 2, 4\}$ 和 $\{7\}$ 则不是。

The first line of input contains a non-negative integer n (1 ≤ n ≤ 100) — the length of the sequence.

The second line contains n space-separated non-negative integers _a_1, _a_2, ..., a__n (0 ≤ a__i ≤ 100) — the elements of the sequence.

输入的第一行包含一个非负整数 $n$（$1 \leq n \leq 100$）—— 表示序列的长度。

第二行包含 $n$ 个用空格分隔的非负整数 $a_1,\,a_2,\,...,\,a_n$（$0 \leq a_i \leq 100$）—— 表示序列的元素。

Output "Yes" if it's possible to fulfill the requirements, and "No" otherwise.

You can output each letter in any case (upper or lower).

如果可以满足要求，则输出“Yes”；否则输出“No”。

您可以以任意大小写形式输出每个字母（大写或小写）。

In the first example, divide the sequence into 1 subsegment: {1, 3, 5} and the requirements will be met.

In the second example, divide the sequence into 3 subsegments: {1, 0, 1}, {5}, {1}.

In the third example, one of the subsegments must start with 4 which is an even number, thus the requirements cannot be met.

In the fourth example, the sequence can be divided into 2 subsegments: {3, 9, 9}, {3}, but this is not a valid solution because 2 is an even number.

在第一个例子中，将序列划分为 1 个子段：{1, 3, 5}，即可满足要求。

在第二个例子中，将序列划分为 3 个子段：{1, 0, 1}、{5}、{1}。

在第三个例子中，某个子段必须以 4（一个偶数）开头，因此无法满足要求。

在第四个例子中，序列可被划分为 2 个子段：{3, 9, 9}、{3}，但这不是有效解，因为 2 是一个偶数。