Roma works in a company that sells TVs. Now he has to prepare a report for the last year.

Roma has got a list of the company's incomes. The list is a sequence that consists of *n* integers. The total income of the company is the sum of all integers in sequence. Roma decided to perform exactly *k* changes of signs of several numbers in the sequence. He can also change the sign of a number one, two or more times.

The operation of changing a number's sign is the operation of multiplying this number by -1.

Help Roma perform the changes so as to make the total income of the company (the sum of numbers in the resulting sequence) maximum. Note that Roma should perform exactly *k* changes.
The first line contains two integers *n* and *k* (1 ≤ *n*, *k* ≤ 10<sup class="upper-index">5</sup>), showing, how many numbers are in the sequence and how many swaps are to be made.

The second line contains a non-decreasing sequence, consisting of *n* integers *a*<sub class="lower-index">*i*</sub> (|*a*<sub class="lower-index">*i*</sub>| ≤ 10<sup class="upper-index">4</sup>).

The numbers in the lines are separated by single spaces. Please note that the given sequence is sorted in non-decreasing order.
#include <bits/stdc++.h>
using namespace std;
#define pie (3.141592653589)
#define int long long int
#define ll long long
#define float double
#define sz(x) (ll)(x).size()
#define len(c) (ll) c.length()
#define pb push_back
#define pf push_front
#define mk make_pair
#define ff first
#define ss second
#define vi vector<int>
#define vpi vector<pair<int, int>>
#define invvi(name, r, c, val) vector<vector<int>> name(r, vector<int>(c, val))
#define vvi vector<vi>
#define unique(v) (v).erase(unique(all(v)), (v).end())
#define trav(it, mp) for (auto it : mp)
#define pi pair<int, int>
#define endl '\n'
#define lb lower_bound
#define ub upper_bound
#define all(c) c.begin(), c.end()
#define rrep(i, n) for (int i = n - 1; i >= 0; i--)
#define rep(i, n) for (int i = 0; i < n; i++)
#define repa(i, a, b) for (int i = a; i < b; i++)
#define fast ios_base::sync_with_stdio(false), cin.tie(nullptr), cout.tie(nullptr);
const int N = 1e6 + 10, mod = 1e9 + 7, INF = 1e9 + 10;
 
void solve()
{
    int n,k,l=0,sum=0,sumi=0;
    cin>>n>>k;
    vi v(n);
    rep(i,n){
        cin>>v[i];
        if(v[i]<0) sumi+=v[i];
        if(v[i]>0)sum+=v[i];
    }
    sort(v.begin(),v.end());
    int i=0,t=0;
    while(k--&&v[i]<0){
        t+=(v[i]*-1);
        sumi+=(v[i]*-1);
        i++;
    }
    cout<<(sum+t+sumi)<<endl;
}
 
int32_t main()
{
    fast
    // int t = 1;
    // cin >> t;
    // while (t--)
    // {
        solve();
    // }
 
    return 0;
}