Parity
题意翻译
## 题目描述:
求$\sum_{i=1}^{k} a_i\times b^{k-i}$的奇偶性。
(如果看不懂上面式子的可以去看英语题目)
## 输入格式:
第一行:$b$和$k$
第二行:$a_1,a_2,...,a_k$
## 输出格式:
- 是奇数:输出`odd`
- 是偶数:输出`even`
题目描述
You are given an integer $ n $ ( $ n \ge 0 $ ) represented with $ k $ digits in base (radix) $ b $ . So,
$n = a_1 \cdot b^{k-1} + a_2 \cdot b^{k-2} + \ldots a_{k-1} \cdot b + a_k. $
For example, if $ b=17, k=3 $ and $ a=\[11, 15, 7\] $ then $ n=11\\cdot17^2+15\\cdot17+7=3179+255+7=3441 $
Determine whether $ n$ is even or odd.
输入输出格式
输入格式
The first line contains two integers $ b $ and $ k $ ( $ 2\le b\le 100 $ , $ 1\le k\le 10^5 $ ) — the base of the number and the number of digits.
The second line contains $ k $ integers $ a_1, a_2, \ldots, a_k $ ( $ 0\le a_i < b $ ) — the digits of $ n $ .
The representation of $ n $ contains no unnecessary leading zero. That is, $ a_1 $ can be equal to $ 0 $ only if $ k = 1 $ .
输出格式
Print "even" if $ n $ is even, otherwise print "odd".
You can print each letter in any case (upper or lower).
输入输出样例
输入样例 #1
13 3
3 2 7
输出样例 #1
even
输入样例 #2
10 9
1 2 3 4 5 6 7 8 9
输出样例 #2
odd
输入样例 #3
99 5
32 92 85 74 4
输出样例 #3
odd
输入样例 #4
2 2
1 0
输出样例 #4
even
说明
In the first example, $ n = 3 \cdot 13^2 + 2 \cdot 13 + 7 = 540 $ , which is even.
In the second example, $ n = 123456789 $ is odd.
In the third example, $ n = 32 \cdot 99^4 + 92 \cdot 99^3 + 85 \cdot 99^2 + 74 \cdot 99 + 4 = 3164015155 $ is odd.
In the fourth example $ n = 2 $ .