using System;
using System.Linq;

public class Kumite
{
  public static int Digits(ulong n)
  {
    //GEEEEEEET DUUUUUUNKED OOOOOOOOOOOOOON
    int theseDigitsShouldREALLYBeCountedImSureOfIt = n
    .ToString()
    .ToCharArray()
    .Select((c,i)=>new{_char = c, ShouldBeCounted = true, index = i})
    .Select((a,i)=>new{charValue = a._char-'0', shouldREALLYbecounted = a.ShouldBeCounted && a.index==i})
    .OrderBy(a=>a.charValue)
    .ToArray()
    .Where(a=>a.shouldREALLYbecounted.ToString()=="True")
    .ToList()
    .ToArray()
    .Length;
    
    
    int thatNameWasTooLong = theseDigitsShouldREALLYBeCountedImSureOfIt;
    int soWasThatOne = thatNameWasTooLong;
    int betterstill = soWasThatOne;
    int thisone = betterstill;
    int _this = thisone;
    int _ = _this;
    return _;
   } 
}