program DZ1;

{$APPTYPE CONSOLE}

uses
  SysUtils;

type
  masiv=array[1..1000]of Integer;

const
  N=6;
  C=3;
var
  A: array [1..N, 1..C] of Integer;

  procedure zamena (var A: masiv);
  var i,j,t:Integer;
  ms_a: array [1..N, 1..C] of Integer;
  begin
    for i:=1 to N div 2 do begin
      for j:=1 to C do begin
        t:= ms_a[2*i - 1, j];
        ms_a[2*i - 1, j]:= ms_a[2*i, j];
        ms_a[2*i, j]:= t;
      end;
    end;
  end;

  function random_mas ():masiv;
  var i,j:Integer;
  begin
  Randomize;
  for i:=1 to N do begin
    for j:=1 to C do begin
      A[i,j] := random  (50);
      write (A[i,j]:5);
    end;
    writeln;
  end;
  writeln;
  end;

  function vivod (var A: masiv):integer;
  var i,j:Integer;
  begin
   for i:=1 to N do begin
    for j:=1 to C do begin
      write (A[i,j]:5);
    end;
    writeln;
  end;
  writeln;
  end;

begin
 random_mas ();
 zamena(A:masiv);
 vivod();
 readln;
end.