include <bits/stdc++.h>

using namespace std; deque<pair<int, int>>qmin; long long dp[100001]; int main() {

int n,k;
long long sum=0;
cin>>n>>k;
qmin.push_back({0,0});
for(int i=1;i<=n;i++){
	int val;
	cin>>val;
	sum+=val;
	if(!qmin.empty()&&qmin.front().second+k<i){
		qmin.pop_front();
	}
	dp[i]=dp[i-1];
	while(!qmin.empty()&&qmin.back().first>=dp[i]){
		qmin.pop_back();
	}
	qmin.push_back({sum-dp[i],i});
	dp[i]=min(dp[i],sum-qmin.front().first);
}
cout<<dp[n];
return 0;

}