let s=Array(readLine()!.characters)

var i = 0
var fuminikui = 0
for i in 1...s.count {
  if( ( i % 2 ) == 1 ) {
    if( s[i-1] == "L" ) {
      fuminikui = 1
    }
  } else if ( s[i-1] == "R" ) {
    fuminikui = 1
  }
}

if ( fuminikui == 1 ) {
  print( "No" )
} else {
  print( "Yes" )
}