//#include<iostream>

 #include<cstring>

 #include<cstdio>

 //#include<time.h>

 //#include<complex>

 //#include<set>

 #include<queue>

 //#include<vector>

 #include<algorithm>

 #include<stdlib.h>

 using namespace std;

 #define LL long long

 int qread()

 {

     char c; int s=,f=; while ((c=getchar())<'' || c>'') (c=='-') && (f=-);

     do s=s*+c-''; while ((c=getchar())>='' && c<=''); return s*f;

 }

 //Pay attention to '-' , LL and double of qread!!!!

 int n,m;

 #define maxn 50011

 #define LL long long

 LL Abs(LL x) {return x>?x:-x;}

 int a[maxn]; LL sum[maxn];

 int b[maxn],lb,ll[maxn],rr[maxn]; bool vis[maxn];

 struct qnode

 {

     LL v; int id;

     bool operator > (const qnode &b) const {return v>b.v;}

 };

 priority_queue<qnode,vector<qnode>,greater<qnode> > q;

 int main()

 {

     n=qread(); m=qread();

     for (int i=;i<=n;i++) a[i]=qread();

     {

         int L=,R=n; while (a[L]<=) L++; while (a[R]<=) R--;

         for (int i=L,j=;i<=R;i++,j++) a[j]=a[i];

         n=R-L+; a[n+]=;

     }

     for (int i=;i<=n;i++) sum[i]=sum[i-]+a[i];

     LL ans=;

     int cnt=;

     {

         LL tmp=a[],last=;

         for (int i=;i<=n+;i++)

         {

             if (tmp> && a[i]<=)

             {

                 b[++lb]=last;

                 q.push((qnode){tmp,lb});

                 ans+=tmp; cnt++; tmp=a[i]; last=i;

             }

             else if (tmp> && a[i]>) tmp+=a[i];

             else if (tmp<= && a[i]>)

             {

                 b[++lb]=last;

                 q.push((qnode){-tmp,lb});

                 tmp=a[i]; last=i;

             }

             else tmp+=a[i];

         }

     }

     for (int i=;i<=lb+;i++) ll[i]=i-,rr[i]=i+; b[lb+]=n+;

     if (cnt<=m) {printf("%lld\n",ans); return ;}

     while (m<cnt--)

     {

         while (vis[q.top().id]) q.pop();

         ans-=q.top().v; int now=q.top().id; q.pop();

         if (ll[now]==)

         {

             vis[rr[now]]=;

             vis[now]=;

             int u=rr[now]; ll[rr[now]]=ll[now]; rr[ll[now]]=rr[now];

             ll[rr[u]]=ll[u]; rr[ll[u]]=rr[u];

         }

         else if (rr[now]==lb+)

         {

             vis[ll[now]]=;

             vis[now]=;

             int u=ll[now]; ll[rr[now]]=ll[now]; rr[ll[now]]=rr[now];

             ll[rr[u]]=ll[u]; rr[ll[u]]=rr[u]; b[lb+]=b[u];

         }

         else

         {

             int L=b[ll[now]],R=b[rr[rr[now]]]-;

             vis[ll[now]]=; vis[rr[now]]=; int u=ll[now],v=rr[now];

             b[now]=L; q.push((qnode){Abs(sum[R]-sum[L-]),now});

             ll[rr[u]]=ll[u]; rr[ll[u]]=rr[u];

             ll[rr[v]]=ll[v]; rr[ll[v]]=rr[v];

         }

     }

     printf("%lld\n",ans);

     return ;

 }