#include <bits/stdc++.h> using namespace std; int main() { ios::sync_with_stdio(false); cin.tie(nullptr); int N, K; cin >> N >> K; vector<long long> A(N); for (int i = 0; i < N; i++) cin >> A[i]; vector<long long> pos, neg; for (int i = 0; i < N; ) { long long s = 0; int j = i; if (A[i] >= 0) { while (j < N && A[j] >= 0) s += A[j++]; pos.push_back(s); } else { while (j < N && A[j] < 0) s += A[j++]; neg.push_back(s); } i = j; } if (pos.empty()) { cout << 0 << "\n"; return 0; } priority_queue<long long> pq; long long ans = 0; int m = pos.size(); for (long long x : pos) { ans += x; pq.push(x); } for (int i = 0; i + 1 < m; i++) { pq.push(pos[i] + pos[i + 1] + neg[i]); } while ((int)pq.size() > K) { ans -= pq.top(); pq.pop(); } cout << ans << "\n"; return 0; }