#include "bits/stdc++.h"
using namespace std;
int main(){
ios_base::sync_with_stdio(0);
cin.tie(0);
int n, k;
cin>>n>>k;
deque<long long> a;
for(int i = 0; i < n; i++){
long long v;
cin>>v;
if(v == 0) continue;
if(a.empty()) a.push_back(v);
else if((a.back() / abs(a.back())) == (v / abs(v))) a.back() += v;
else a.push_back(v);
}
while(!a.empty() and a[0] < 0) a.pop_front();
while(!a.empty() and a.back() < 0) a.pop_back();
n = a.size();
if(n == 0){
cout<<0;
return 0;
}
vector< vector< vector<long long> > > PD(2, vector< vector<long long> >(k + 1, vector<long long>(2, 0)));
long long Respuesta = 0;
for(int i = n - 1; i > -1; i--){
for(int j = 1; j <= k; j++){
PD[0][j][0] = max(PD[1][j][0], PD[1][j][1]);
PD[0][j][1] = max(PD[1][j][1], PD[1][j - 1][0]) + a[i];
Respuesta = max(Respuesta, max(PD[0][j][0], PD[0][j][1]));
}
PD[0][0][0] = max(PD[1][0][0], PD[1][0][1]);
PD[0][0][1] = -2222222222222222;
swap(PD[0], PD[1]);
}
cout<<Respuesta;
return 0;
}
