#include <bits/stdc++.h>
using namespace std;

int main() {
	int n; cin >> n;
	int x, y; cin >> x >> y;
	vector<int> arr(n);
	for(int i = 0; i < n; i++)
	cin >> arr[i];
	
	int area = (x-1)*y; int sum = 0;
	for(int i = 0; i <= area; i++){
		if(i%y == 0)
		sum += arr[i];
	}
	int ans = sum;
	int i = 0; int j = area;
	while(j<n){
		sum -= arr[i];
		i = i+y;
		j = j+y;
		if(j <= n){
		sum += arr[j];
		ans = min(sum,ans);
		}
	}
	cout << ans;
	return 0;
}