#include<iostream>

using namespace std;

int main(void)
{
	string S;

	cin >> S;

	int r,i,tmp=0;

	r=S.size();

	for(i=0;i<r;i++)
	{
		if(i%2==0 && S[i]=='L')
			tmp=1;
		if(i%2==1 && S[i]=='R')
			tmp=1;

	}

	if(tmp==1)
		cout << "No" << endl;

	else
		cout << "Yes" << endl;

}
