记录编号	113214	评测结果	AAAAAAAAAA
题目名称	[IOI 1999]矩形地块（A Strip of Land）	最终得分	100
用户昵称	teacher	是否通过	通过
代码语言	Pascal	运行时间	1.966 s
提交时间	2014-07-19 23:02:39	内存使用	4.03 MiB

var
c,q:byte;
u,v,i,j,k,max,right,x:integer;
ans:longint;
di:array[-30000..30010] of integer;
p,f,h,g:array[1..701,0..700] of integer;
begin
 assign(input,'land.in'); reset(input);
 assign(output,'land.out'); rewrite(output);
 readln(u,v,c);
 for i:=1 to v do p[i,0]:=30001;
 for i:=1 to u do p[v+1,i]:=30001;
 c:=c+1;
 for i:=1 to v do for j:=1 to u do read(h[i,j]);
 for i:=0 to c-1 do di[i]:=0;
 for i:=-1 downto -30000 do di[i]:=di[i+c]-1;
 for i:=c to 30010 do di[i]:=di[i-c]+1;
for q:=0 to c-1 do begin
 for i:=1 to v do for j:=1 to u do p[i,j]:=di[h[i,j]+q];
 for i:=1 to u do begin
  f[1,i]:=1;
  for j:=2 to v do
   if p[j,i]=p[j-1,i] then f[j,i]:=f[j-1,i]+1
    else f[j,i]:=1;
 end;
 for i:=1 to v do begin
  g[i,u]:=1;
  for j:=u-1 downto 1 do
   if p[i,j]=p[i,j+1] then begin g[i,j]:=g[i,j+1]+1; if g[i,j]>100 then g[i,j]:=100 end
    else g[i,j]:=1;
 end;
for i:=1 to u do
 for j:=v downto 1 do begin
  if (p[j,i]=p[j+1,i]) and (g[j,i]<=g[j+1,i]) then continue;
  if (p[j,i]=p[j,i-1]) and (f[j,i]<=f[j,i-1]) then continue;
   max:=f[j,i];
   if f[j,i]>ans then ans:=f[j,i];
   if i=u then continue;
   right:=i+g[j,i]-1;
   for k:=i+1 to right do begin
    if f[j,k]<max then max:=f[j,k];
    if max*(k-i+1)>ans then ans:=max*(k-i+1);
   end;
 end;
end;
 writeln(ans);
 close(input); close(output);
end.