Двумерные числовые массивы

Uses Crt;
const
n=6;
var
a:array[1..n,1..n] of integer;
b:array[1..n*n] of integer;
i,j:byte;
s,mx,k:integer;
begin
for i:=1 to n do 
for j:=1 to n do 
a[i,j]:=random(-25,25);
for i:=1 to n do begin
for j:=1 to n do
write(a[i,j]:4);
writeln; end;
mx:=a[1,2]; 
for i:=1 to n do begin
if a[i,2]>mx then begin
mx:=a[i,2]; end; end;
writeln('max el 2 stb=',mx);
k:=0;
for i:=1 to n do begin
for j:=1 to n do 
if a[i,j] mod 3=0 then begin
inc(k); end; end; k:=0;
writeln('kol-vo el krat 3=',k);
writeln('mass iz el <5:',k);
for i:=1 to n do begin
for j:=1 to n do 
if a[i,j]<5 then begin
b[i]:=a[i,j];
inc(k); write(b[i]:4); end; end;
s:=0; k:=0;
for i:=1 to n do begin
for j:=1 to n do 
if a[i,j]>=0 then begin
s:=s+a[i,j]; inc(k);
end; end;
if k=0 then begin
writeln('v matrix net pol el'); 
end else  writeln; writeln('summ pol el mtrx=',s);
for j:=1 to n do begin
s:=0; k:=0;
for i:=1 to n do begin
if a[i,j]>=0 then begin
s:=s+a[i,j]; inc(k);
end; end;
if k=0 then begin
writeln('v stolve ',j,' net pol el');
end else writeln('v stolbe ',j,' summ pol el=',s);
end;
end.