#include<cstdio>
#include<cstring>
#define MAXN 1<<6
#define MAXC 1<<9
#define max(a,b) a>b?a:b
using namespace std;
int n,m,a[MAXN][MAXN],pre[MAXN][MAXN],f[MAXN][MAXN][MAXC],ans;
inline int in(){
	char c=getchar();
	int x=0;
	while(c<'0'||c>'9')c=getchar();
	for(;c>='0'&&c<='9';c=getchar())x=x*10+c-'0';
	return x;
}
void Dynamic_Programming(void){
	for(int i=1;i<=n;i++)
		for(int j=0;j<=i;j++){
			for(int k=j;k<=m;k++)
				for(int l=(j-1<0)?0:j-1;l<i;l++)
					f[i][j][k]=max(f[i][j][k],f[i-1][l][k-j]+pre[i][j]);
			ans=max(ans,f[i][j][m]);
		}
	return ;
}
int main()
{	
	freopen("brike.in","r",stdin),freopen("brike.out","w",stdout),n=in(),m=in();
	memset(f,-0x3f,sizeof f);
	
	for(int j=1;j<=n;j++)
		for(int i=n;i>=j;i--)
			a[i][j]=in();
	for(int i=1;i<=n;i++)
		for(int j=1;j<=i;j++)
			pre[i][j]=pre[i][j-1]+a[i][j];
	ans=0,f[0][0][0]=0,Dynamic_Programming(),printf("%d",ans);
	return 0;
}