#include<bits/stdc++.h>
using namespace std;
#ifdef LOCAL_JUDGE
#include<local_debug>
#else
#define debug(...) 1
#endif
#define ls (p<<1)
#define rs (p<<1|1)
#define pb push_back
#define int long long
#define eb emplace_back
#define lowbit(x) (x&-x)
#define rint register int
#define alls(a) a.begin(),a.end()
#define mem(a,b) memset(a,b,sizeof a)
typedef long long ll;
typedef __int128 i128;
typedef long double ld;
typedef unsigned long long ull;
typedef pair<int,int> pii;
bool ST;
const int inf=0x3f3f3f3f;
const ll INF=1e18;
template<typename T>
void read(T &x){
x=0;int f=1;char c=getchar();
while(!isdigit(c)){if(c=='-') f=-1;c=getchar();}
while(isdigit(c)){x=x*10+c-'0';c=getchar();}
x*=f;
}
template<typename T,typename ... Args>
void read(T &x, Args &... y){read(x);read(y...);}
namespace Mr_Az{
const int N=3e5+8;
int T=1;
int n,k,m=1,ans,cnt;
bool f=0;
int a[N],b[N],pre[N],nxt[N];
bool vis[N];
priority_queue<pii,vector<pii>,greater<pii>> q;
priority_queue<pii> q1;
inline int abs(int x){return x<0?-x:x;}
inline void solve(){
read(n,k);
for(rint i=1;i<=n;i++) read(a[i]);
for(rint i=1;i<=n;i++){
f|=(a[i]>0);
if(f){
m+=!((a[i-1]<=0&&a[i]<=0)||(a[i-1]>0&&a[i]>0));
b[m]+=a[i];
}
}
if(a[n]<0) m--;
// for(rint i=1;i<=m;i++) cerr<<b[i]<<" ";cerr<<endl;
b[0]=b[m+1]=0;
mem(vis,1);
for(rint i=1;i<=m;i++){
pre[i]=i-1;nxt[i]=i+1;
if(b[i]<=0) q1.push({b[i],i});
else q.push({b[i],i}),cnt++;
}
if(cnt<=k){
for(rint i=1;i<=m;i++) ans+=(b[i]>0)*b[i];
goto end;
}
while(cnt>k){
int x1=INF,i1,x2=-INF,i2;
while(q.size()){
auto tt=q.top();
x1=tt.first,i1=tt.second;
if(!vis[i1]) q.pop();
else break;
}
while(q1.size()){
auto tt=q1.top();
x2=tt.first,i2=tt.second;
if(!vis[i2]) q1.pop();
else break;
}
if(x1<-x2){
q.pop();
cnt--;
b[i1]=b[pre[i1]]+x1+b[nxt[i1]];
if(b[pre[i1]]>0) cnt--;
if(b[nxt[i1]]>0) cnt--;
if(b[i1]<=0) q1.push({b[i1],i1});
else q.push({b[i1],i1}),cnt++;
// cerr<<"com1 "<<pre[i1]<<" "<<i1<<" "<<nxt[i1]<<" "<<b[i1]<<" "<<cnt<<endl;
vis[pre[i1]]=vis[nxt[i1]]=0;
int pr=pre[pre[i1]],nx=nxt[nxt[i1]];
nxt[pr]=i1;
pre[i1]=pr;
pre[nx]=i1;
nxt[i1]=nx;
}
else{
q1.pop();
b[i2]=-inf;
if(b[pre[i2]]>0) cnt--;
if(b[nxt[i2]]>0) cnt--;
if(b[i2]<=0) q1.push({b[i2],i2});
else q.push({b[i2],i2}),cnt++;
// cerr<<"com2 "<<pre[i2]<<" "<<i2<<" "<<nxt[i2]<<" "<<b[i2]<<" "<<cnt<<endl;
vis[pre[i2]]=vis[nxt[i2]]=0;
int pr=pre[pre[i2]],nx=nxt[nxt[i2]];
nxt[pr]=i2;
pre[i2]=pr;
pre[nx]=i2;
nxt[i2]=nx;
}
}
while(q.size()) ans+=vis[q.top().second]*q.top().first,q.pop();
end:
printf("%lld\n",ans);
return ;
}
inline void mian(){if(!T) read(T);while(T--) solve();}
}
bool ED;
signed main(){
// freopen(".in","r",stdin);
// freopen(".out","w",stdout);
auto st=clock();
Mr_Az::mian();
auto ed=clock();
cerr<<endl;
cerr<<"Time: "<<ed-st<<" ms\n";
cerr<<"Memory: "<<abs(&ST-&ED)/1024.0/1024.0<<" MB\n";
return 0;
}
