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();
}
}