робот

#include <iostream>
#include <string>
#include <sstream>
#include <cmath>
#include <algorithm>
#include <memory.h>
#include <stdio.h>
#include <vector>
#include <stack>
#include <deque>
#include <queue>
#include <vector>
#include <set>
#include <iterator>
#include <map>
#include <iomanip>
#define int long long
using namespace std;

signed main()
{
    int n, k;
    cin >> n >> k;

    int mas[100000];

    for (int i = 0; i < n; i++)
    {
        cin >> mas[i];
    }

    sort(mas, mas + n);

    // first

    int ans1 = 0;
    int use1 = 0;

    for (int i = 0; i < n; i++)
    {
        if (use1 < k && mas[i] < 0)
        {
            use1++;

            ans1 += - mas[i];
        }
        else
        {
            ans1 += mas[i];
        }
    }

    // second

    int ans2 = 0;
    int use2 = 0;

    for (int i = n - 1; i >= 0; i--)
    {
        if (use2 < k && mas[i] > 0)
        {
            use2++;

            ans2 += -mas[i];
        }
        else
        {
            ans2 += mas[i];
        }
    }

    cout << max(abs(ans1), abs(ans2));

    return 0;

}