for x1:=1 to m-n+1 do
for y1:=1 to m-n+1 do
try(x1,y1);
枚举每个攻击范围正方形的左上角
procedure try(p,q:integer);
var
k:integer;
begin
if max=n*n then exit 如果发现已经有整个正方形被攻击那就没有必要继续找下去了（优化）
else
begin
k:=0;
for i:=p to p+n-1 do
for j:=q to q+n-1 do
if a[i,j]=1 then inc(k); 统计当前正方形的被攻击的数量
end;
if k>max then max:=k; 更新最大值
end;

program p1199;
var
a:array[1..10000,1..10000]of boolean;
b,i,j,k,l,n,m,ans:longint;
x:char;
begin
//assign(input,'fuck.txt');reset(input);
// assign(output,'fuck2.txt');rewrite(output);
fillchar(a,sizeof(a),false);
readln(n);readln(m);
for i:=1 to n do
begin
for j:=1 to n do
begin
read(x);if x='#' then a[i,j]:=true;
end;
readln;
end;
ans:=0;
for i:=m to n do
for j:=m to n do
begin
b:=0;
for k:=i-m+1 to i do
for l:=j-m+1 to j do
if a[k,l] then inc(b);
if b>ans then ans:=b;
end;
writeln(ans);
end.
AC

program P1199;

var
n,m,k,j,i:longint;
a:array[1..100,1..100]of char;

procedure ds(q,w:longint);
var i,j,l:longint;
begin
l:=0;
for i:=q to q+m-1 do
for j:=w to w+m-1 do
if a[i,j]='#' then inc(l);
if l>k then k:=l;
end;

begin
readln(n,m);
k:=0;
for i:=1 to n do
for j:=1 to n do read(a[i,j]);
for i:=1 to n-m+1 do
for j:=1 to n-m+1 do
ds(i,j);
write(k);
end.