Untitled

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

int main() {  
    int N, K;  
    cin >> N >> K;  
    vector<int> candles(N);  

    for (int i = 0; i < N; ++i) {  
        cin >> candles[i];  
    }  
    
    int low = 0;           
    int high = 0;               
    long long minTime = LLONG_MAX;

    while (high < N) {  
        if (high - low + 1 < K) {  
            high++; 
        }   
     
        else {  
            int leftCandle = candles[low];     
            int rightCandle = candles[high];   
             
            long long time = abs(leftCandle) + (rightCandle - leftCandle);  
            minTime = min(minTime, time);  

            low++;
            high++;  
        }  
    }  

    cout << minTime << endl;  

    return 0;  
}