#include <bits/stdc++.h>   using namespace std;   long long a[100005], n, c, mn[100005], dp[200005], sum;   int main() {     ios_base::sync_with_stdio(0);     cin >> n >> c;     for (int i = 0; i < n; sum += a[i++]) cin >> a[i];     deque<long long> v;     for (int i = n; i--;) {       while (v.size() && v.back() >= i + c) v.pop_back();       while (v.size() && a[i] <= a[v.front()]) v.pop_front();       v.push_front(i);       if (i <= n - c) dp[i] = max(dp[i + 1], a[v.back()] + dp[i + c]);     }     cout << sum - dp[0];   }   