ll@n,@k,@a[n],o=0,t=0;
rep(i,n){
	if(a[i]<0){
		o+=a[i];
		a[i]=-a[i];
	}
	t+=a[i];
}
unordered_set<int>s;
priority_queue<pair<ll,int>>q;
q.push({t,0});
rep(k-1){
	auto b=q.top();
	q.pop();
	rep(i,n){
		int c=b.second|1<<i;
		if(c!=b.second&&s.insert(c).second){
			q.push({b.first-a[i],c});
		}
	}
}
wt(q.top().first+o);