using System.Collections.Generic;
public static void Main()
var userIds = "18,42,46,64,65,117";
List<long> listOfUserIds = userIds?.Split(",")?.Select(str => long.TryParse(str, out userId))?.Select(str => userId)?.ToList();
List<long> appraiserOrder = new List<long>();
var soem = appraiserOrder?.Select(x => x)?.ToList()?.Intersect(listOfUserIds)?.Any();