#include <bits/stdc++.h>
#define st first
#define nd second
using lint = int64_t;
constexpr int mod = int(1e9) + 7;
constexpr int inf = 0x3f3f3f3f;
constexpr int ninf = 0xcfcfcfcf;
constexpr lint linf = 0x3f3f3f3f3f3f3f3f;
const long double pi = acosl(-1.0);
// Returns -1 if a < b, 0 if a = b and 1 if a > b.
int cmp_double(double a, double b = 0, double eps = 1e-9) {
return a + eps > b ? b + eps > a ? 0 : 1 : -1;
}
using namespace std;
using dbl = long double;
const lint INF = 3.1e14;
int main() {
cin.tie(nullptr)->sync_with_stdio(false);
int n, k;
cin>>n>>k;
vector<int>a(n);
for(int i=0;i<n;i++) cin>>a[i];
dbl lo = 0, hi = INF;
for(int z=0;z<100;z++){
dbl mid = (lo + hi) / 2;
vector<array<pair<dbl, int>, 2>>dp(n+1);
dp[0][0] = {0, 0}, dp[0][1] = {-INF, 0};
for(int i=0;i<n;i++){
dp[i+1][1] = max(make_pair(dp[i][1].st + a[i], dp[i][1].nd),
make_pair(dp[i][0].st + a[i] - mid, dp[i][0].nd + 1));
dp[i+1][0] = max(dp[i][0], dp[i][1]);
}
if(max(dp[n][0], dp[n][1]).nd >= k) lo = mid;
else hi = mid;
}
dbl mid = hi;
vector<array<dbl, 2>>dp(n+1);
dp[0][0] = 0, dp[0][1] = -INF;
for(int i=0;i<n;i++){
dp[i+1][1] = max(dp[i][1] + a[i], dp[i][0] + a[i] - mid);
dp[i+1][0] = max(dp[i][0], dp[i][1]);
}
cout<< lint(round(max(dp[n][0], dp[n][1]) + mid * k))<<"\n";
return 0;
}
/*
[ ]Leu o problema certo???
[ ]Ver se precisa de long long
[ ]Viu o limite dos fors (é n? é m?)
[ ]Tamanho do vetor, será que é 2e5 em vez de 1e5??
[ ]Testar sample
[ ]Testar casos de borda
[ ]1LL no 1LL << i
[ ]Testar mod (é 1e9+7, mesmo?, será que o mod não ficou negativo?)
*/
