#include <algorithm>
#include <cstring>
#include <vector>

#define DIM 20005
#define infile "ferma.in"
#define outfile "ferma.out"

const int inf = 2000000000;

int chickensProductivity[DIM];

int partialSum[DIM];

int deque[DIM];

int main() {

	freopen(infile, "r", stdin);
	freopen(outfile, "w", stdout);

	int chickenCount, collectCount;

	scanf("%d%d", &chickenCount,  &collectCount);

	for (int chicken = 1; chicken <= chickenCount; ++chicken) {

		scanf("%d", chickensProductivity + chicken);

		chickensProductivity[chicken + chickenCount] = chickensProductivity[chicken];

	}


	int solution = 0;

	for (int collect = 1; collect <= collectCount; ++collect) {

		int left = 1, right = 1;

		deque[1] = 0;

		int currAns = -inf, leftEndAns, rightEndAns;

		for (int chicken = 1; chicken < 2 * chickenCount; ++chicken) {

			partialSum[chicken] = partialSum[chicken - 1] + chickensProductivity[chicken];

			if (left <= right && chicken - deque[left] == chickenCount) {

				++left;

			}


			if (partialSum[chicken] - partialSum[deque[left]] > currAns) {

				currAns = partialSum[chicken] - partialSum[deque[left]];

				leftEndAns = deque[left] + 1;

				rightEndAns = chicken;

			}

			while (left <= right && partialSum[chicken] <= partialSum[deque[right]]) {

				--right;

			}

			deque[++right] = chicken;

		}

		for (int chicken = leftEndAns; chicken <= rightEndAns; ++chicken) {

			int temp = (chicken <= chickenCount ? chicken : chicken - chickenCount);

			chickensProductivity[temp] *= -1;
			chickensProductivity[temp + chickenCount] *= -1;

		}

		solution += currAns;

	}


	printf("%d", solution);

	return 0;

}

//Trust me, I'm the Doctor!