var
     mas: array [1..100] of integer;
     mas2: array [1..100, 1..100] of integer;
     n, k, str, f, i, j, kol: integer;

begin
     readln(n, k);
        {for i:=1 to  n do read mas[i];}
        {Считаем кол-во строк}
     if n mod k <> 0 then str := (n div k) + 1 else str := n div k;
        {Считаем "полную" матрицу}
     kol := k * str;
     for i := 1 to n do read(mas[i]);
        {Заполняем "-1" будущие пустые места}
     for i := n + 1 to kol do mas[i] := -1;
     f := 1;
     for i := 1 to k do
          for j := 1 to str do
          begin
               mas2[j, i] := mas[f];
               inc(f);
          end;
     for i := 1 to str do
     begin
          for j := 1 to k do
               if mas2[i, j] <> -1 then write(mas2[i, j]:4) else continue;
          writeln;
     end;
end.