#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define pll pair<ll,ll>
#define pii pair<int,int>
#define fs first
#define sc second
#define tlll tuple<ll,ll,ll>
const ll inf = 1e13;
const int mxn = 3e5+10;
ll arr[mxn];
ll pref[mxn];
pll dp[mxn];
ll N,K;
inline pll calc(ll p){
pll pt = make_pair(0,0);
for(int i = 1;i<=N;i++){
dp[i] = dp[i-1];
dp[i] = max(dp[i],make_pair(pref[i]+pt.fs-p,pt.sc+1));
pt = max(pt,make_pair(dp[i].fs-pref[i],dp[i].sc));
}
return dp[N];
}
int main(){
ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);
cin>>N>>K;
for(int i = 1;i<=N;i++){
cin>>arr[i];
pref[i] = arr[i]+pref[i-1];
}
ll l = -inf,r = inf;
while(l != r){
ll mid = l+(r-l+1)/2;
if(calc(mid).sc>=K)l = mid;
else r = mid-1;
}
auto re = calc(l);
ll ans = re.fs+l*K;
re = calc(0);
if(re.sc<=K)ans = max(ans,re.fs);
cout<<ans;
}
