#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef long double ld;
#define rep(a, b) for(int a = 0; a < (b); ++a)
#define st first
#define nd second
#define pb push_back
#define all(a) a.begin(), a.end()
struct Node {
ll pref;
int ind_pref;
ll inv_pref;
int inv_ind_pref;
ll suf;
int ind_suf;
ll inv_suf;
int inv_ind_suf;
ll psoms;
int indl_psoms, indr_psoms;
ll inv_psoms;
int inv_indl_psoms, inv_indr_psoms;
ll sum;
int lazy;
};
const int LIM=1<<20, INF=1e9+7;
ll T[LIM], N=1, n, k;
Node tr[2*LIM], pusty;
void inv(int v) {
swap(tr[v].pref, tr[v].inv_pref);
swap(tr[v].ind_pref, tr[v].inv_ind_pref);
swap(tr[v].suf, tr[v].inv_suf);
swap(tr[v].ind_suf, tr[v].inv_ind_suf);
swap(tr[v].psoms, tr[v].inv_psoms);
swap(tr[v].indl_psoms, tr[v].inv_indl_psoms);
swap(tr[v].indr_psoms, tr[v].inv_indr_psoms);
tr[v].sum*=-1;
tr[v].lazy^=1;
}
void spl(int v) {
inv(2*v);
inv(2*v+1);
tr[v].lazy=0;
}
void lacz(int v) {
tr[v].pref=tr[2*v].pref; tr[v].ind_pref=tr[2*v].ind_pref;
if(tr[2*v].sum+tr[2*v+1].pref>tr[v].pref) {
tr[v].pref=tr[2*v].sum+tr[2*v+1].pref;
tr[v].ind_pref=tr[2*v+1].ind_pref;
}
tr[v].suf=tr[2*v+1].suf; tr[v].ind_suf=tr[2*v+1].ind_suf;
if(tr[2*v+1].sum+tr[2*v].suf>tr[v].suf) {
tr[v].suf=tr[2*v+1].sum+tr[2*v].suf;
tr[v].ind_suf=tr[2*v].ind_suf;
}
tr[v].psoms=tr[2*v].psoms;
tr[v].indl_psoms=tr[2*v].indl_psoms; tr[v].indr_psoms=tr[2*v].indr_psoms;
if(tr[2*v+1].psoms>tr[v].psoms) {
tr[v].psoms=tr[2*v+1].psoms;
tr[v].indl_psoms=tr[2*v+1].indl_psoms; tr[v].indr_psoms=tr[2*v+1].indr_psoms;
}
if(tr[2*v].suf+tr[2*v+1].pref>tr[v].psoms) {
tr[v].psoms=tr[2*v].suf+tr[2*v+1].pref;
tr[v].indl_psoms=tr[2*v].ind_suf; tr[v].indr_psoms=tr[2*v+1].ind_pref;
}
tr[v].inv_pref=tr[2*v].inv_pref; tr[v].inv_ind_pref=tr[2*v].inv_ind_pref;
if(-tr[2*v].sum+tr[2*v+1].inv_pref>tr[v].inv_pref) {
tr[v].inv_pref=-tr[2*v].sum+tr[2*v+1].inv_pref;
tr[v].inv_ind_pref=tr[2*v+1].inv_ind_pref;
}
tr[v].inv_suf=tr[2*v+1].inv_suf; tr[v].inv_ind_suf=tr[2*v+1].inv_ind_suf;
if(-tr[2*v+1].sum+tr[2*v].inv_suf>tr[v].inv_suf) {
tr[v].inv_suf=-tr[2*v+1].sum+tr[2*v].inv_suf;
tr[v].inv_ind_suf=tr[2*v].inv_ind_suf;
}
tr[v].inv_psoms=tr[2*v].inv_psoms;
tr[v].inv_indl_psoms=tr[2*v].inv_indl_psoms; tr[v].inv_indr_psoms=tr[2*v].inv_indr_psoms;
if(tr[2*v+1].inv_psoms>tr[v].inv_psoms) {
tr[v].inv_psoms=tr[2*v+1].inv_psoms;
tr[v].inv_indl_psoms=tr[2*v+1].inv_indl_psoms; tr[v].inv_indr_psoms=tr[2*v+1].inv_indr_psoms;
}
if(tr[2*v].inv_suf+tr[2*v+1].inv_pref>tr[v].inv_psoms) {
tr[v].inv_psoms=tr[2*v].inv_suf+tr[2*v+1].inv_pref;
tr[v].inv_indl_psoms=tr[2*v].inv_ind_suf; tr[v].inv_indr_psoms=tr[2*v+1].inv_ind_pref;
}
tr[v].sum=tr[2*v].sum+tr[2*v+1].sum;
}
void upd(int v, int l, int r, int a, int b) {
if(b<l || a>r) return;
if(a<=l && r<=b) {
inv(v);
return;
}
if(tr[v].lazy) spl(v);
int mid=(l+r)/2;
upd(2*v, l, mid, a, b);
upd(2*v+1, mid+1, r, a, b);
lacz(v);
}
ll dynamiczny_psoms(int x) {
rep(i, 2*N) tr[i]=pusty;
rep(i, n) tr[N+i]={T[i], i, -T[i], i, T[i], i, -T[i], i, T[i], i, i, -T[i], i, i, T[i], 0};
for(int i=N-1; i; --i) lacz(i);
ll ans=0;
while(x--) {
if(tr[1].psoms<=0) break;
ans+=tr[1].psoms;
upd(1, 0, N-1, tr[1].indl_psoms, tr[1].indr_psoms);
}
return ans;
}
int main() {
ios_base::sync_with_stdio(0); cin.tie(0);
cin >> n >> k;
k=min(n, k);
while(N<n) N*=2;
rep(i, n) cin >> T[i];
cout << dynamiczny_psoms(k) << '\n';
}
