#include <bits/stdc++.h>
using namespace std;
int main() {
  char a, c;
  int b, d;
  cin >> a >> b >> c >> d;
  int x, y;
  x = c - a;
  y = d - b;
  cout << max(labs(x), labs(y)) << endl;
  while (max(labs(x), labs(y))) {
    if (x > 0)
      cout << "R";
    else if (x < 0)
      cout << "L";
    if (y > 0)
      cout << "U";
    else if (y < 0)
      cout << "D";
    cout << endl;
    if (x) x -= x / labs(x);
    if (y) y -= y / labs(y);
  }
}
