import java.util.*;

public class Solution { public String compressString (String param) { if(param.length()==0) return ""; StringBuilder sb=new StringBuilder(); int sum=1; for(int i=0;i<param.length()-1;i++){ if(param.charAt(i)==param.charAt(i+1)){ sum++; }else{ sb.append(param.charAt(i)); if(sum>1){ sb.append(sum);
} sum=1; } } sb.append(param.charAt(param.length()-1)); if(sum>1){ sb.append(sum); } return sb.toString(); } }