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