#include <iostream>
#include <fstream>
#include <deque>
#include <climits>
#include <algorithm>
using namespace std;

int main()
{
    ifstream fin("deque.in");
    ofstream fout("deque.out");
    int n, k, x, mn = INT_MAX;
    long long sum = 0;
    fin >> n >> k;
    deque<int> d;
    for(int i = 1; i <= k; i++) {
        fin >> x;
        d.push_back(x);
        mn = min(mn, x);
    }
    sum += mn;
    for(int i = k + 1; i <= n; i++) {
        d.pop_front();
        fin >> x;
        d.push_back(x);
        if(find(d.begin(), d.end(), x) != d.end()) {
            mn = INT_MAX;
            for(auto j : d) mn = min(mn, j);
        }
        sum += mn;
    }
    fout << sum;
    return 0;
}