#include <bits/stdc++.h>
using namespace std;
using ll = long long;

int main() {
    cin.tie(nullptr);
    ios_base::sync_with_stdio(false);
    ll N, K;
    cin >> N >> K;
    vector<ll> A(N);
    ll max = 0;
    for(ll& a : A) {
        cin >> a;
        if(a >= 0) max += a;
        else a = -a;
    }
    static bitset<1 << 30> used;
    priority_queue q(greater<>{}, vector<pair<ll, int>>{});
    auto push = [&](int bit, ll cost) {
        if(used[bit]) return;
        used[bit] = 1;
        q.emplace(cost, bit);
    };
    push(0, 0);
    while(1) {
        auto [c, bit] = q.top();
        q.pop();
        if(--K == 0) {
            cout << max - c << endl;
            return 0;
        }
        for(int i = 0; i < N; i++) if(~bit & 1 << i) push(bit | 1 << i, c + A[i]);
    }
}