"use strict";
    
const main = arg => {
    arg = arg.trim().split("\n");
    const S = arg[0].split("");
    
    let answer = "Yes";
    
    for(let i in S) {
        if(i % 2 === 0 && S[i] === "L") {
            answer = "No";
            break;
        }
        
        if(i % 2 !== 0 && S[i] === "R") {
            answer = "No";
            break;
        }
    }

    console.log(answer);
}
main(require('fs').readFileSync('/dev/stdin', 'utf8'));