Uses CRT;
Var
  s1, s2 : string[50];
  c : char;
  len, position : byte;
  k : word;
  dir : integer;
Begin
  dir := 0;
  k := 0;
  ClrScr;
  TextColor(7);
  GotoXY(5,8);
  Write('Введите строку ');
  Readln(s1);
  len := length(s1) +1;
  ClrScr;
  GotoXY(10,2);
  Write('Stand : ');
  GotoXY(10,4);
  Write('Slide :');
  GotoXY(30,10);
  Write('Result : ');
  GotoXY(30,2);
  Write(s1);
  Position := 15;
  c := #12;
  repeat
    if keypressed then begin
      c := readkey;
      repeat
        k := random(15);
        TextColor(k);
      until (k <> 8) and (k <> 0);
      if c = #0 then c := readkey;
       case c of
        #77 : begin
                if length(s2) < len -1 then Begin
                  insert(s1[1],s2,Length(s2) + 1);
                  delete(s1,1,1);
                  GotoXY(20,2);
                  ClrEOL;
                  GotoXY(30 + (len-length(s1)-1), 2);
                  Write(s1);
                  GotoXY(29,4);
                  ClrEOL;
                  GotoXY(30,4);
                  Write(s1);
                end;
              end;
        #75 : begin
                if length (s2) > 0 then begin
                  insert(s2[length(s2)],s1,1);
                  GotoXY(30 + len - length(s1)-1,2);
                  ClrEOL;
                  Write(s1);
                  GotoXY(30,4);
                  ClrEOL;
                  Write(s1);
                  Delete(s2,length(s2),1);
                end;
             end;
      end;
  end;
  GotoXY(1,12);
  ClrEOL;
  GotoXY(position,12);
  Write(s2);
  repeat
    k := random(1000);
  until k > 10;
  Delay (k);
  if position < 2 then dir := 1;
  if position + length(s2) > 79 then dir := 0;
  if dir = 0 then dec(position)
  else inc(position);
  until c = #27;
  TextColor(7);
  ClrScr;
end.