#include<bits/stdc++.h>
#define ll long long
#define int long long
#define pii pair<int,int>
#define tiii tuple<int,int,int>
using namespace std;
vector<int> arr;
int n,k;
int INF = numeric_limits<int>::max()/2;
pii calc(int lambda){
vector<vector<pii>> dp(2, vector<pii>(n));
dp[0][0] = {0,0};
dp[1][0] = {arr[0],1};
for(int i = 1; i < n; i++){
dp[0][i] = max(dp[0][i-1], dp[1][i-1]);
dp[1][i] = max(make_pair(dp[0][i-1].first - lambda + arr[i], dp[0][i-1].second),
make_pair(dp[1][i-1].first+arr[i], dp[1][i-1].second));
}
return max(dp[0][n-1], dp[1][n-1]);
}
int32_t main(){
cin >> n >> k;
arr.resize(n);
for(int i = 0; i < n; i++){
cin >> arr[i];
}
int l = 0, r = INF;
int val = 0;
while(l <= r){
int mid = (l+r)/2;
auto cur = calc(mid);
if(cur.second > k){
l = mid+1;
val = mid;
}else{
r = mid-1;
}
}
pii res = calc(val+1);
cout << res.first + (k*(val+1)) << endl;
}
