#include <iostream>
#include <vector>
using namespace std;
const int N = 1<<17;
int strt[N], dp[N][201], a[N];
int intersection(int i1, int i2, int k){
int m1 = a[i1], m2 = a[i2], c1 = dp[i1][k] - a[i1] * a[i1], c2 = dp[i2][k] - a[i2] * a[i2];
int x = (c2 - c1 + (m1 - m2 - 1)) / (m1 - m2);
return x;
}
int main(){
int n, K;
cin>>n>>K;
for (int i=1;i<=n;i++){
cin>>a[i], a[i] += a[i-1];
if (a[i] == a[i-1])
i--, K -= (K == n), n--;
}
for (int k=1;k<=K;k++){
vector<int> vec;
for (int i=1;i<=n;i++){
// cout<<i<<" "<<k<<endl;
int l = 0, r = vec.size();
while (l + 1 < r){
int mid = (l + r) / 2;
if (strt[vec[mid]] <= a[i])
l = mid;
else
r = mid;
}
// cout<<i<<" "<<k<<endl;
if (vec.size() > 0){
// cout<<i<<" "<<k<<" "<<vec[l]<<endl;
dp[i][k] = dp[vec[l]][k-1] + a[vec[l]] * (a[i] - a[vec[l]]);
}
// cout<<i<<" "<<k<<endl;
while (vec.size() > 0 and intersection(vec.back(), i, k-1) <= strt[vec.back()])
vec.pop_back();
// cout<<i<<endl;
if (vec.size() > 0)
strt[i] = intersection(vec.back(), i, k - 1);
vec.push_back(i);
// cout<<i<<" "<<k<<endl;
}
// cout<<k<<" :: ";
// for (int i=1;i<=n;i++)
// cout<<dp[i][k]<<' ';
// cout<<'\n';
}
cout<<dp[n][K-1]<<'\n';
}
