#include<bits/stdc++.h>
using namespace std;
int main()
{
    string s;
    bool v=true;
    cin>>s;
	for(int i=0;i<s.size();i+=2)
		if(s[i]=='L'||s[i+1]=='R')
			v=false;
	if(v==true)
		cout<<"Yes";
	else
		cout<<"No";
} 