#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];

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