simint 1

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

///************************************************
int solve(int n, int k, const vector<int> &v)
{
    if (k > n) {
        return 0;
    }
    int sum = 0, maxSum = INT_MIN;
    for (int i = 0; i < k; i++)
        sum += v[i];
    if (sum > maxSum)
    {
        maxSum = sum;
    }
    for (int i = k; i < n; i++)
    {
        sum -= v[i - k];
        sum += v[i];
        if (sum > maxSum)
        {
            maxSum = sum;
        }
    }
    int totalSum = 0;
    for (int i = 0; i < n; i++)
        totalSum += v[i];
    if (maxSum == INT_MIN)
    {
        maxSum = 0;
    }
    return totalSum - maxSum;
}

int main()
{
    int n, k;
    cin >> n >> k;
    vector<int> v(n);
    for (int &nr : v) {
        cin >> nr;
    }
    cout << solve(n, k, v) << endl;
    return 0;
}