The king is left alone on the chessboard. In spite of this loneliness, he doesn't lose heart, because he has business of national importance. For example, he has to pay an official visit to square *t*. As the king is not in habit of wasting his time, he wants to get from his current position *s* to square *t* in the least number of moves. Help him to do this.

In one move the king can get to the square that has a common side or a common vertex with the square the king is currently in (generally there are 8 different squares he can move to).
The first line contains the chessboard coordinates of square *s*, the second line — of square *t*.

Chessboard coordinates consist of two characters, the first one is a lowercase Latin letter (from a to h), the second one is a digit from 1 to 8.
program exm;

type
  W08 = Byte;
  W16 = Word;
  W32 = LongWord;
  W64 = UInt64;

  Z08 = ShortInt;
  Z16 = SmallInt;
  Z32 = LongInt;
  Z64 = Int64;

  F32 = Single;
  F64 = Double;

function IndexOf(a: Char; b: String): Z64;
  var
    c: Z64 = 1;
    d: Z64;
  begin
    d := Length(b);
    while not (d < c) do
      begin
        if b[c] = a then
          begin
            Exit(c);
          end;
        c := c + 1;
      end;
  end;

function Fyle(a: Char): Z64;
  const
    B: String = 'abcdefgh';
  begin
    Exit(IndexOf(a, B));
  end;

function Rank(a: Char): Z64;
  const
    B: String = '12345678';
  begin
    Exit(IndexOf(a, B));
  end;

function Abs(a: Z64): Z64;
  begin
    if not (a < 0) then
      begin
        Exit(a);
      end
    else
      begin
        Exit(- a);
      end;
  end;

function Max(a: Z64; b: Z64): Z64;
  begin
    if a < b then
      begin
        Exit(b);
      end
    else
      begin
        Exit(a);
      end;
  end;

function Distance(a: Z64; b: Z64; c: Z64; d: Z64): Z64;
  var
    e: Z64;
    f: Z64;
    g: Z64;
  begin
    e := Abs(a - c);
    f := Abs(b - d);
    g := Max(e, f);
    Exit(g);
  end;

function Direction(a: z64; b: Z64; c: Z64; d: Z64): String;
  const
    E: String = 'S';
    F: String = 'L';
    G: String = 'R';
    H: String = 'U';
    I: String = 'D';
    J: String = 'LU';
    K: String = 'LD';
    L: String = 'RU';
    M: String = 'RD';
  var
    n: Z64;
    o: Z64;
  begin
    n := c - a;
    o := d - b;
    if n = 0 then
      begin
        if o = 0 then
          begin
            Exit(E);
          end
        else
          begin
            if 0 < o then
              begin
                Exit(H);
              end
            else
              begin
                Exit(I);
              end;
          end;
      end
    else
      begin
        if 0 < n then
          begin
            if o = 0 then
              begin
                Exit(G);
              end
            else
              begin
                if 0 < o then
                  begin
                    Exit(L);
                  end
                else
                  begin
                    Exit(M);
                  end;
              end;
          end
        else
          begin
            if o = 0 then
              begin
                Exit(F);
              end
            else
              begin
                if 0 < o then
                  begin
                    Exit(J);
                  end
                else
                  begin
                    Exit(K);
                  end;
              end;
          end;
      end;
  end;

procedure Path(a: Z64; b: Z64; c: Z64; d: Z64);
  const
    E: Array [1 .. 3] of Z64 = ((- 1), 0, 1);
  var
    f: Z64;
    g: Z64;
    h: Z64;
    i: Z64;
    j: Z64;
    k: Z64;
    l: Z64;
    m: Z64;
  begin
    if (a = c) and (b = d) then
      begin
        Exit();
      end;
    k := Distance(a, b, c, d);
    for f := Low(E) to High(E) do
      begin
        g := a + E[f];
        if (0 < g) and (g < 9) then
          begin
            for h := Low(E) to High(E) do
              begin
                i := b + E[h];
                if (0 < i) and (i < 9) then
                  begin
                    j := Distance(g, i, c, d);
                    if j < k then
                      begin
                        k := j;
                        l := g;
                        m := i;
                      end;
                  end;
              end;
          end;
      end;
    WriteLn(Direction(a, b, l, m));
    Path(l, m, c, d);
  end;

procedure Exm(a: String; b: String);
  var
    c: Z64;
    d: Z64;
    e: Z64;
    f: Z64;
    g: Z64;
  begin
    c := Fyle(a[1]);
    d := Rank(a[2]);
    e := Fyle(b[1]);
    f := Rank(b[2]);
    g := Distance(c, d, e, f);
    WriteLn(g);
    Path(c, d, e, f);
  end;

var
  a: String;
  b: String;
begin
  ReadLn(a);
  ReadLn(b);
  Exm(a, b);
end.
