#include <bits/stdc++.h>
using namespace std;
int main() {
  std::ios::sync_with_stdio(false);
  std::cin.tie(NULL);
  std::cout.tie(NULL);
  char a, b;
  int x1, y1, x2, y2;
  cin >> a >> y1 >> b >> y2;
  x1 = a - 48;
  x2 = b - 48;
  int cnt = 0;
  int minn = min(abs(x2 - x1), abs(y2 - y1)),
      maxx = max(abs(x2 - x1), abs(y2 - y1));
  if (x1 >= x2 && y1 >= y2) {
    cnt += maxx;
    cout << cnt << endl;
    for (int i = 0; i < minn; ++i) {
      cout << "LD" << endl;
    }
    if (abs(y2 - y1) > abs(x2 - x1)) {
      for (int i = 0; i < maxx - minn; ++i) {
        cout << "D" << endl;
      }
    } else {
      for (int i = 0; i < maxx - minn; ++i) {
        cout << "L" << endl;
      }
    }
  } else if (x1 >= x2 && y1 <= y2) {
    cnt += maxx;
    cout << cnt << endl;
    for (int i = 0; i < minn; ++i) {
      cout << "LU" << endl;
    }
    if (abs(y2 - y1) > abs(x2 - x1)) {
      for (int i = 0; i < maxx - minn; ++i) {
        cout << "U" << endl;
      }
    } else {
      for (int i = 0; i < maxx - minn; ++i) {
        cout << "L" << endl;
      }
    }
  } else if (x1 <= x2 && y1 >= y2) {
    cnt += maxx;
    cout << cnt << endl;
    for (int i = 0; i < minn; ++i) {
      cout << "RD" << endl;
    }
    if (abs(y2 - y1) > abs(x2 - x1)) {
      for (int i = 0; i < maxx - minn; ++i) {
        cout << "D" << endl;
      }
    } else {
      for (int i = 0; i < maxx - minn; ++i) {
        cout << "R" << endl;
      }
    }
  } else if (x1 <= x2 && y1 <= y2) {
    cnt += maxx;
    cout << cnt << endl;
    for (int i = 0; i < minn; ++i) {
      cout << "RU" << endl;
    }
    if (abs(y2 - y1) > abs(x2 - x1)) {
      for (int i = 0; i < maxx - minn; ++i) {
        cout << "U" << endl;
      }
    } else {
      for (int i = 0; i < maxx - minn; ++i) {
        cout << "R" << endl;
      }
    }
  }
  return 0;
}
