let xs = (stdin.ReadLine()).ToCharArray()
let mutable odd = true
let mutable even = true
for i in 0..xs.Length-1 do
    if (i+1) % 2 <> 0 then
        if xs.[i] <> 'R' && xs.[i] <> 'U' && xs.[i] <> 'D' then
            odd <- false
    else
        if xs.[i] <> 'L' && xs.[i] <> 'U' && xs.[i] <> 'D' then
            even <- false
printfn "%s" (if odd && even then "Yes" else "No")