// what is matter? never mind. 
#pragma GCC optimize("Ofast")
#pragma GCC optimize("unroll-loops")
//#pragma GCC target("sse,sse2,sse3,sse4,popcnt,abm,mmx,avx,avx2") 
#include<bits/stdc++.h>
#define For(i,a,b) for(int i=(a);i<=(b);++i)
#define Rep(i,a,b) for(int i=(a);i>=(b);--i)
#define ll long long
#define int long long
#define ull unsigned long long
#define SZ(x) ((int)((x).size()))
#define ALL(x) (x).begin(),(x).end()
using namespace std;
inline int read()
{
    char c=getchar();int x=0;bool f=0;
    for(;!isdigit(c);c=getchar())f^=!(c^45);
    for(;isdigit(c);c=getchar())x=(x<<1)+(x<<3)+(c^48);
    if(f)x=-x;return x;
}

#define fi first
#define se second
#define pb push_back
#define mkp make_pair
typedef pair<int,int>pii;
typedef vector<int>vi;
 
#define maxn 10005
#define inf 0x3f3f3f3f3f3f3f3f

int n,c,a[maxn],up;
int sum[maxn];

int w(int j,int i){
	return sum[j]+a[i];
}
int f[10005][10005];

signed main()
{
	n=read(),c=read();
	For(i,1,n)a[i]=read();
	sort(a+1,a+n+1);
	if(n<=c)cout<<a[n],exit(0);
	
	For(i,1,n)sum[i]=sum[i-1]+a[i];
	up=n/c;
	For(i,0,n)For(j,0,up)f[i][j]=inf;
	
	f[0][0]=0;
	For(i,1,n){
//		cout<<"i: "<<i<<"\n";
		if(i<=c) f[i][0]=min(f[i][0],w(0,i));
		For(j,0,(n-i)/c+1){
			For(k,0,j+1){
				if(k>c) break;
				// 1....i   -> j<-
				if(i>=c+1 && i-(c-k)>=0 && k<c)
					f[i][j]=min(f[i][j],w(k,i)+f[i-(c-k)][j-(k-1)]);
				// 1..k  + (l..i) --> , 1...k <--
				if(i<=c && k>=1 && k<=c)
					f[i][j]=min(f[i][j],w(k,i)+f[k][j-(k-1)]);
				// 1..i -->, 1..k <--- , 1..k -->
				
			}
		}
		
//		For(j,0,up){
//			cout<<f[i][j]<<" ";
//		}cout<<"\n";
		
	}
	cout<<f[n][0];
	return 0;
}
/*
4 2
1 2 5 10
7 2
1 2 4 5 7 10 14
7 3
2 2 2 3 6 6 6
*/