#include <bits/stdc++.h>   using namespace std;   int main() {     int n, k;     cin >> n >> k;     bool zero = false;     int *arr = new int[n];     for (int i = 0; i < n; i++) {       cin >> arr[i];     }     int neg = 0;     for (int i = 0; i < n; i++) {       if (arr[i] < 0) neg++;       if (arr[i] == 0) {         zero = true;       }     }     for (int i = 0; k > 0 && i < neg;) {       arr[i] = arr[i] * -1;       k--;       i++;     }     long long int ans = 0;     for (int i = 0; i < n; i++) {       ans += arr[i];     }     int min = INT_MAX;     for (int i = 0; i < n; i++) {       if (arr[i] < min) {         min = arr[i];       }     }     if (k % 2 == 0) {       cout << ans;     } else {       cout << ans - 2 * min;     }     return 0;   }   