program PascalGuru;
label 1;
var
A: array [1 .. 100, 1 .. 100] of integer; { переменная массива }
i, j, n: integer; { переменные для циклов }
{ ------------------------------------ }
procedure exchange(var A, b: integer);
var
c: integer;
begin
c := A;
A := b;
b := c;
end;
{ ------------------------------------ }
begin
1:
write('Vvedite razmer matricy A: ');
readln(n);
if n < 4 then
begin
writeln('N doljno byti bolishe 4!');
writeln;
goto 1;
end;
for i := 1 to n do
for j := 1 to n do
begin
write('A[', i, ',', j, ']=');
readln(A[i, j]);
end;
write('Vot vvedennai vami matrica A: ');
for i := 1 to n do
begin
writeln;
for j := 1 to n do
write(A[i, j]:8);
end;
for j := 1 to n do
exchange(A[1, j], A[3, j]);
for j := 1 to n do
exchange(A[2, j], A[4, j]);
writeln;
writeln;
write('Vot PREOBRAZOVANNAYA matrica A: ');
for i := 1 to n do
begin
writeln;
for j := 1 to n do
write(A[i, j]:8);
end;
readln;
end.