import java.util.*;
import java.lang.*;
 
class Main
{
	public static void main (String[] args) throws java.lang.Exception
	{
		System.out.println(encode("WWWWWWWWWBBBCC"));	
	}
	private static String encode(String input){
		char[] chars=input.toCharArray();
		char c=chars[0];
		String output="";int runLength=1;
		System.out.println(chars.length);
		for(int i=1;i<chars.length;i++){
			if(c==chars[i] && i!=chars.length-1){
				runLength++;
			}else if(i==chars.length-1){
			      runLength++;
			      output+=runLength+""+c;
			}
			else{
				output+=runLength+""+c;
				runLength=1;
			}
			c=chars[i];
		}
	return output;
	}
	//private static String decode(String output){
	//}
}

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