#include<bits/stdc++.h>
using namespace std;
using ll=long long;
using pii=pair<int,int>;
#define f first
#define s second
#define eb emplace_back
#define sz(x) (int)x.size()
#define add(x,y) ((((x)+(y))%md+md)%md)
#define Add(x,y) (x=add(x,y))
#define mul(x,y) ((((x)*(y))%md+md)%md)
#define Mul(x,y) (x=mul(x,y))
template<class T> T chmn(T &x,T y){ return x=min(x,y); }
template<class T> T chmx(T &x,T y){ return x=max(x,y); }
const int inf=1e9;
const ll linf=1e18;
const ll md=1e9+7;
// const ll md=119<<23|1;
ll a[300005];
pair<ll,ll> dp[300005];
void calc(int n,ll c){
pair<ll,ll> mx(0,0);
for(int i=1;i<=n;++i){
dp[i] = max(dp[i-1], {mx.f+a[i]-c, mx.s-1});
chmx(mx, {dp[i].f-a[i], dp[i].s});
}
}
void solve(){
int n,k; cin>>n>>k;
for(int i=1;i<=n;++i) cin>>a[i], a[i]+=a[i-1];
ll l=0,r=1e15;
while(l<r){
ll mid=l+r>>1;
calc(n,mid);
if(-dp[n].s<=k) r=mid;
else l=mid+1;
}
calc(n,l);
cout << dp[n].f+l*k;
}
int main(){
ios::sync_with_stdio(false); cin.tie(0);
int Q(1);
// cin>>Q;
while(Q--) solve();
}
/*
6 1
1 -2 3 -1 5 -6
6 2
1 2 3 -10 5 6
*/
