Task_E

#include <iostream>
#include <vector>
#include <climits>

using namespace std;
int main() {
    int cowsAmount;
    int stallsAmount;
    vector<int> coordinates;
    //Ввод данных
    cin >> stallsAmount;
    cin >> cowsAmount;
    int k = 0;
    while (k != stallsAmount){
        int temp;
        cin >> temp;
        coordinates.push_back(temp);
        k++;
    }

    //Тело программы
    int l1 = 0;
    int r1 = stallsAmount-1;
    cowsAmount-=2;
    int minDist = INT_MAX;
    while (cowsAmount){
        int m = (coordinates[l1]+coordinates[r1])/2;
        int tempInd;
        int tempMin = coordinates[r1];
        for (int i = l1; i < r1/2+2; i++){
            if (abs(m-coordinates[i]) < tempMin){
                tempMin = abs(m-coordinates[i]);
                tempInd = i;
            }
        }
        if (abs(coordinates[l1] - coordinates[tempInd]) < abs(coordinates[tempInd] - coordinates[r1])){
            r1 = tempInd;
        } else l1 = tempInd;
        cowsAmount--;
    }
    minDist = coordinates[r1] - coordinates[l1];
    cout << minDist;
    return 0;
}