#include <iostream>
#include <map>
#include <vector>
#include <climits>
#include <stack>
#include <string>
#include <queue>
#include <algorithm>
#include <set>
#include <unordered_set>
#include <iostream>
#include <unordered_map>
#include <cmath>
#include <cctype>
#include <bitset>
#include <iomanip>
#include <cstring>
using namespace std;
#define int long long
#define pii pair<int, int>
#define mp make_pair
int n;
vector<int> vect, psum;
vector<pii> dp;
pii pmax(pii a, pii b){
if (a.first==b.first)return a.second<b.second?a:b;
return a.first>b.first?a:b;
}
pii feast(int pen){
dp[0]=mp(0, 0);
pii best=mp(0, 0);
for (int i=1; i<=n; ++i){
dp[i]=pmax(dp[i-1], mp(best.first+psum[i]-pen, best.second+1));
best=pmax(best, mp(dp[i].first-psum[i], dp[i].second));
}
return dp[n];
}
int32_t main(){
int k;
cin>>n>>k;
vect.resize(n+1);
dp.resize(n+1);
psum.resize(n+1, 0);
for (int i=1; i<=n; ++i)cin>>vect[i], psum[i]=psum[i-1]+vect[i];
int low=-1, high=LLONG_MAX/100000;
while (low+1<high){
int mid = (low+high)/2;
if (feast(mid).second>=k)low=mid;
else high=mid;
}
pii res=feast(low);
cout<<res.first+res.second*low;
}
