function main(input) {
  var kisu = true
  var gusu = true
  for(var i = 0; i < input.length; i+= 1){
      var a = input[i]
      if((i + 1) % 2 != 0){
          if(a != "R" && a != "U" && a != "D"){
              kisu = false
          }
      }else{
           if(a != "L" && a != "U" && a != "D"){
              gusu = false
          }
      }
  }
  if(kisu && gusu){
      console.log("YES")
  }else{
      console.log("NO")
  }
}

main(require('fs').readFileSync('/dev/stdin', 'utf8'));