ADAMOLD - Ada and Mold

## 题目描述 您可能已经知道，Ada是一个农民。她有很长的犁沟，可以在上面种菜（每种菜都用开花值确定）。犁沟中的蔬菜越多，发霉的风险就越大。更具体地，霉菌值可以作为所有成对的蔬菜开花值的异或之和而获得。 Ada购买了一些木制隔板，这可能会降低模具价值。它的工作方式如下：她可以将分隔符放在某些植物之间，将犁沟分成多个部分。然后，模具值将成为所有段的模具值的总和（独立地）。您能找到最小的霉菌价值吗？ ## 输入格式 输入的第一行包含两个整数N，K： 1，犁沟的长度和分隔符的数量。 接下来的行将包含N个数字0，即蔬菜的开花值。 ## 输出格式 输出最小可能的模数值。 ## 输入输出样例 无

As you might already know, Ada the Ladybug is a farmer. She has a long furrow in which she grows vegetable (while each vegetable is indentified by a bloom-value). The more vegetable is in the furrow the bigger risk of mold there is. More specificaly the mold-value can be obtained as sum of **xor** of all pairs of vegetable's bloom-values. Ada has bought a few wooden separators which could possibly reduce the mold-value. It works in following manner: she can put the separators between some plants, dividing the furrow into multiple segments. The mold-value will then becomes the sum of mold-values of all the segments (independently). Can you find the minimal possible mold-value?

The first line of input containts two integers **N, K**: **1 , the length of furrows and the number of separators.** The next lines will contain **N** numbers **0 , the bloom-values of vegetable.**

Output the minimal possible mold-value.