program task_d;

{$APPTYPE CONSOLE}

uses
  SysUtils;

var
  n,m,i,j,ans,max:integer;
  a:array[0..1001,0..1001] of longint;
  s:array[1..1000] of boolean;
  f:text;

  function fmax(a,b:longint):longint;
  begin
  if (a>=b) then fmax:=a else fmax:=b;
  end;

  procedure pr(c:integer);
  var
  i:integer;
  begin
  if (c=(n+1)) then begin max:=fmax(ans,max);  end
  else
  begin

  for i:=1 to n do
  begin
  if (s[i]) then begin ans:=ans+a[c,i]; s[i]:=false; pr(c+1); s[i]:=true; ans:=ans-a[c,i]; end;
  end;

  end;

  end;



begin
assign(f,'legacy.in');
reset(f);
readln(f,n,m);

for i:=1 to n do
begin
for j:=1 to n do  read(f,a[i,j]);
readln(f);
end;
close(f);
max:=0;
ans:=0;
fillchar(s,sizeof(s),true);
pr(1);



assign(f,'legacy.out');
rewrite(f);
writeln(f,max);
close(f);
  { TODO -oUser -cConsole Main : Insert code here }
end.