using System; using System.IO; using System.Linq; using System.Collections.Generic; using System.Text; public class Program { public void Proc() { string inpt = Reader.ReadLine(); string ans = "NO"; if(inpt.Length == inpt.Distinct().Count()) { ans = "YES"; } Console.WriteLine(ans); } public class Reader { static StringReader sr; public static bool IsDebug = false; public static string ReadLine() { if (IsDebug) { if (sr == null) { sr = new StringReader(InputText.Trim()); } return sr.ReadLine(); } else { return Console.ReadLine(); } } private static string InputText = @" YUKICODER "; } public static void Main(string[] args) { #if DEBUG Reader.IsDebug = true; #endif Program prg = new Program(); prg.Proc(); } }