#include<iostream>
#include<string>
using namespace std;
string s;
bool check(int i){
	if(i%2==1&&s[i]=='R')return 1;
	if(i%2==0&&s[i]=='L')return 1;
	return 0;
}
int main(void){
	cin>>s;
	for(int i=0;i<s.size();i++)
		if(check(i)){cout<<"No";return 0;}
	cout<<"Yes";
	return 0;
}