CoderByte Task 2 - countString

import java.util.*; 
import java.io.*;

class Main {
  
  public static String ReplaceString(String str, String token){
    StringBuilder sb = new StringBuilder();
    for(int i=0; i<str.length(); i++){
      char c = str.charAt(i);
      if(token.contains(Character.toString(c))){
        continue;
      }
      else
        sb.append(c);
    }
    return sb.toString();
  }

  public static String StringChallenge(String str) {
    // code goes here  
    String token = "s1otw2b";
    StringBuilder sb = new StringBuilder();
    int count = 1;
    for(int i=1; i<str.length(); i++){
      if(str.charAt(i) == str.charAt(i-1)){
        count++;
      }
      else{
        sb.append(count).append(str.charAt(i-1));
        count = 1;
      }
    }
    sb.append(count).append(str.charAt(str.length() - 1));
    str = sb.toString();
    
    return ReplaceString(str, token);
  }

  public static void main (String[] args) {  
    // keep this function call here     
    Scanner s = new Scanner(System.in);
    System.out.print(StringChallenge(s.nextLine())); 
  }

}