#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
using ll = long long;
int n, k;
vector <int> t;
const int maxn = 5000 + 1;
ll dp[maxn][maxn];
bool ready[maxn][maxn];
ll solve(int i, int left) {
if (i > n)
return 0;
if (left <= 0 && i <= n)
return 1e18;
if (ready[i][left])
return dp[i][left];
ll ans = 1e18;
for (int j = i; j <= n; j++)
ans = min(ans, solve(j+1, left - 1) + t[j] - t[i] + 1);
ready[i][left] = true;
dp[i][left] = ans;
return ans;
}
int main() {
cin >> n >> k;
t.resize(n+1);
for (int i = 1; i <= n; i++)
cin >> t[i];
cout << solve(1, k) << '\n';
}
