#include <bits/stdc++.h>
using namespace std;
int read() {
  int x;
  scanf("%d", &x);
  return x;
}
long long readL() {
  long long x;
  scanf("%I64d", &x);
  return x;
}
const int MAX = 26;
int chess[8][8], a, b, x, y, res;
string re = "";
int cal(int i, int j) {
  if (i == x && j == y) return 0;
  if (i < x && j > y) {
    re += "RD,";
    res = 1 + cal(i + 1, j - 1);
  } else if (i > x && j < y) {
    re += "LU,";
    res = 1 + cal(i - 1, j + 1);
  } else if (i < x && j < y) {
    re += "RU,";
    res = 1 + cal(i + 1, j + 1);
  } else if (i > x && j > y) {
    re += "LD,";
    res = 1 + cal(i - 1, j - 1);
  } else if (i > x && j == y) {
    re += "L,";
    res = 1 + cal(i - 1, j);
  } else if (i < x && j == y) {
    re += "R,";
    res = 1 + cal(i + 1, j);
  } else if (i == x && j > y) {
    re += "D,";
    res = 1 + cal(i, j - 1);
  } else if (i == x && j < y) {
    re += "U,";
    res = 1 + cal(i, j + 1);
  }
  return res;
}
int main() {
  string s, f;
  cin >> s >> f;
  a = s[0] - 'a' + 1, b = s[1] - '0', x = f[0] - 'a' + 1, y = f[1] - '0';
  cout << cal(a, b) << "\n";
  for (int i = 0; i < re.length(); i++) {
    if (re[i] == ',') {
      cout << "\n";
      continue;
    }
    cout << re[i];
  }
  return 0;
}
