记录编号	39458	评测结果	AAAAAAAAAAAA
题目名称	平衡奶牛	最终得分	100
用户昵称	czp	是否通过	通过
代码语言	Pascal	运行时间	0.725 s
提交时间	2012-07-11 17:47:59	内存使用	23.81 MiB

type aaa=array[0..30] of longint;
var
 op:array[0..100000] of aaa;
 sum:array[0..30,0..100000] of longint;
 p:array[1..33] of longint;
 i,j,m,n,k,tt,min,max,ans:longint;
 mid,tp:aaa;
function pan1(xx,yy:aaa):boolean;
var i:longint;
begin
 pan1:=false;
 for i:=1 to k-1 do
   begin
    if xx[i]<yy[i] then begin pan1:=true; ;break; end;
    if xx[i]>yy[i] then begin pan1:=false; ;break; end;
   end;
end;
function pan2(xx,yy:aaa):boolean;
var i:longint;
begin
 pan2:=false;
 for i:=1 to k-1 do
   begin
    if xx[i]>yy[i] then begin pan2:=true;break; end;
    if xx[i]<yy[i] then begin pan2:=false;break; end;
   end;
end;
function ok(xx,yy:aaa):boolean;
var i:longint;
begin
 ok:=true;
 for i:=1 to k-1 do
   if xx[i]<>yy[i] then
    begin ok:=false;break; end;
end;
procedure sort(l,r:longint);
var i,j:longint;
begin
 i:=l;
 j:=r;
 mid:=op[(l+r) div 2];
 repeat
  while pan1(op[i],mid) do inc(i);
  while pan2(op[j],mid) do dec(j);
  if i<=j then
   begin
    tp:=op[i];
    op[i]:=op[j];
    op[j]:=tp;
    inc(i);
    dec(j);
   end;
 until i>j;
 if i<r then sort(i,r);
 if j>l then sort(l,j);
end;
begin
 assign(input,'balline.in');reset(input);
 assign(output,'balline.out');rewrite(output);
 readln(n,k);
 p[1]:=1;
 for i:=2 to k do p[i]:=p[i-1]*2;
 for i:=1 to n do
  begin
   readln(m);
   for j:=1 to k do
    begin
    sum[j,i]:=sum[j,i-1];
    if m and p[j]=p[j] then inc(sum[j,i]);
    end;
  end;
 tt:=n+1;
 for i:=1 to n do
  begin
  op[i,0]:=i;
  for j:=1 to k-1 do
    op[i,j]:=sum[j+1,i]-sum[j,i];
  end;
 sort(1,tt);
 min:=op[1][0];
 max:=op[1][0];
 for i:=2 to tt do
  begin
   if ok(op[i-1],op[i]) then
    begin
     if op[i][0]<min then min:=op[i][0];
     if op[i][0]>max then max:=op[i][0];
     if max-min>ans then ans:=max-min;
    end else
     begin
        min:=op[i][0];
        max:=op[i][0];
     end;
  end;
 writeln(ans);
 close(input);close(output);
end.