#include <bits/stdc++.h>
using namespace std;
int main()
{
  string s;
  cin >> s;
  string ans = "Yes";
  for (int i=0; i<s.size(); i++) {
    if (i%2 && s[i]=='R') ans = "No";
    if (!(i%2) && s[i]=='L') ans = "No";
  }
  cout << ans << endl;
  return 0;
}