#include <cstdio>
#include <cstdlib>
#include <iostream>
#include <string>
#include <cmath>
#include <algorithm>
#include <vector>
#include <queue>
#include <stack>
#include <map>
#include <set>
#include <cstring>

typedef long long ll;
using namespace std;

#define mod 1000003
#define INF 1000000000
#define LLINF 2000000000000000000LL

#define SIZE 10000

int n,k,a[10];
int sum[10],cc[10];

double dfs(int h){
    double ret = 0;
    
    if(h==n){
        double minav=INF,maxav=0,av;
        
        for(int i=0;i<k;i++){
            if(cc[i]==0)
                return -1;
        }
        
        for(int i=0;i<k;i++){
            av = (double)sum[i]/cc[i];
            
            minav = min(av,minav);
            maxav = max(av,maxav);
        }
        
        return maxav-minav;
        
    }
    
    for(int i=0;i<k;i++){
        sum[i]+=a[h];
        cc[i]++;
        ret = max(ret,dfs(h+1));
        sum[i]-=a[h];
        cc[i]--;
    }
    
    return ret;
}

int main(){
    
    scanf("%d%d",&n,&k);
    
    for(int i=0;i<n;i++)
        scanf("%d",&a[i]);
    
    printf("%d\n",(int)ceil(dfs(0)));
    
    return 0;
}