let S = Array(readLine()!)

let S_size = S.count

var ok:Bool = true

for i in 0..<S_size {
    if i % 2 == 0 {
        if S[i] == "L" {
            ok = false
        }
    }else{
        if S[i] == "R" {
            ok = false
        }
    }
}

if ok {
    print("Yes")
}else {
    print("No")
}