#include <iostream>
#include <string>
#include <algorithm>
#include <vector>
#include <iomanip>
#include <math.h>
#include <complex>
#include <queue>
#include <deque>
#include <stack>
#include <map>
#include <unordered_map>
#include <set>
#include <bitset>
#include <functional>
#include <assert.h>
#define int long
#define ll long long
#define rng(i,a,b) for(int i=int(a);i<int(b);i++)
#define rep(i,b) rng(i,0,b)
#define gnr(i,a,b) for(int i=int(b)-1;i>=int(a);i--)
#define per(i,b) gnr(i,0,b)
#define eb emplace_back
#define all(x) x.begin(),x.end()
#define SZ(x) x.size()
#define fi first
#define se second
const int INF = 1e9;
using namespace std;

template<class t> using vc=vector<t>;
template<class t> using vvc=vc<vc<t>>;

using pi=pair<int,int>;
using vi=vc<int>;

template<class T>
inline bool chmax(T &a,T b){if(a<b){a=b;return true;}return false;}
template<class T>
inline bool chmin(T &a,T b){if(a>b){a=b;return true;}return false;}


double ans=0.0;
int N,K;
int A[10];
void dfs(int n,int sum[],int cnt[]){
    if(n==N){
        bool can=true;
        rep(i,K){
            if(cnt[i]==0) can=false; 
        }
        if(!can) return;
        double mi=(double)sum[0]/cnt[0],ma=(double)sum[0]/cnt[0];
        rep(i,K){
            chmax(ma,(double)sum[i]/cnt[i]);
            chmin(mi,(double)sum[i]/cnt[i]);
        }
        chmax(ans,ma-mi);
        return;
    }
    else{
        rep(i,K){
            sum[i]+=A[n]; cnt[i]++;
            dfs(n+1,sum,cnt);
            sum[i]-=A[n]; cnt[i]--;
        }
    }
}

signed main() {
    cin.tie(0);
    ios::sync_with_stdio(0);
    cout<<fixed<<setprecision(0);

    cin >> N >> K;
    rep(i,N) cin >> A[i];
    int sum[K]={0};
    int cnt[K]={0};
    dfs(0,sum,cnt);
    cout << ceil(ans) << endl;
}