program jinengshu;
var
  f:array[0..10,0..10,0..11,0..100]  of longint;
  sum,a:array[1..10,0..10]of longint;
  i,j,k,l,p,q,max,s,d,n,m:longint;
begin
  assign (input,'skill.in');
  reset (input);
  assign (output,'skill.out');
  rewrite (output);
    readln (n,m);
    for i:=1 to n do
    begin
      for j:=1 to n-i+1 do
      begin
        read (a[i,j]);
        sum[i,j]:=sum[i,j-1]+a[i,j]
      end;
      readln
    end;
    for i:=1 to n do
      for j:=1 to n-i+1 do
        for k:=j to n-i+1 do
          for l:=1 to m do
          begin
            d:=k-j+1;
            if l>=d then
            begin
              max:=0;
              s:=sum[i,k]-sum[i,j-1];
              for p:=j downto 1 do
                for q:=k+1 to n-i+2 do
                  if f[i-1,p,q,l-d]+s>max then
                    max:=f[i-1,p,q,l-d]+s;
              f[i,j,k,l]:=max
            end
          end;
    max:=0;
    for i:=1 to n do
      for j:=1 to n-i+1 do
        for k:=i to n-i+1 do
          if f[i,j,k,m]>max then
            max:=f[i,j,k,m];
    writeln (max);
  close (input);
  close (output)
end.