import java.util.*;
import java.lang.*;

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