const
  n = 10;

var
  i, j, k :integer;
  
  a :array [1..n] of integer;

begin

  write('Исходный массив: ');
  for i:= 1 to n do
    read(a[i]);
  writeln;
   
  for i:= 1 to n-2 do
    for j:= 1 to n-i do
      if (j mod 2 = 0) and (a[j] > a[j+2]) then
      begin
        k:= a[j];
        a[j]:= a[j+2];
        a[j+2]:= k;
      end;
  
  write('После сортировки: ');
  for i:= 1 to n do
    write(a[i],' ');

end.