Двумерный массив

uses crt;
var
a : array[1..50,1..50] of integer;
n,i,j,sum1,sum2,mn : integer;
 
begin
clrscr;
randomize;
writeln('ENter n:');
readln(n);
 
for i:=1 to n do
 begin
 for j:=1 to n do
  begin
  a[i,j] := random(30)+1;
  write(a[i,j]:4);
  end;
  writeln;
  end;
writeln('----------');
{---------}
sum1 := 0;
sum2 := 0;
for i:=1 to n do
 for j:=i+1 to n do
  sum1 := sum1 + a[i,j];
for i:=1 to n do
 for j:=1 to i-1 do
  sum2 := sum2 + a[i,j];
{-------}
if sum1>sum2 then
  begin
  mn := n;
  for i:=n downto 1 do
   if a[mn,n-mn+1]<a[i,n-i+1] then mn := i;
  a[mn,n-mn+1] := a[mn,n-mn+1]*2;
  end
else
  begin
  mn := n;
  for i:=n downto 1 do
   if a[mn,n-mn+1]>a[i,n-i+1] then mn := i;
  a[mn,n-mn+1] := sqr(a[mn,n-mn+1]);
  end;
{-----}
for i:=1 to n do
 begin
 for j:=1 to n do
  write(a[i,j]:4);
 writeln;
 end;
 
readln;
end.