
local function str2tbl(s)
    -- limit of #s is approximately 999959
    local t = {string.byte(s, 1, #s)}
    local char = string.char
    for i=1, #t do
        t[i] = char(t[i])
    end
    return t
end
--
local read = setmetatable({}, {__index = function(t, k) local a = {} for i=1,#k do table.insert(a, string.sub(k, i, i)) end local r = io.read local u = table.unpack return function() return r(u(a)) end end})
local S = str2tbl(read.l())
local easy = true
for i=1,#S do
    if i%2 == 0 then
        if S[i] == 'R' then
            easy=false
            break
        end
    else
        if S[i] == 'L' then
            easy=false
            break
        end
    end
end
print(easy and "Yes" or "No")
