#include<bits/stdc++.h>
using namespace std;
int main(){
    string s;
    cin>>s;
    int f=0;
    for(int i=0;s[i];++i){
        if(i&1){
            if(s[i]=='R')f=1;
        }
        else if(s[i]=='L')f=1;
    }
    if(f)cout<<"No"<<endl;
    else cout<<"Yes"<<endl;
}
