one test case failed
code
import java.util.;
public class Main {
public static void main(String args[]) {
Scanner s1= new Scanner(System.in);
String s=s1.nextLine();
StringBuilder sb=new StringBuilder(s);
int n=sb.length();
for(int i=0;i<2n-2;i=i+2) {
int c=sb.charAt(i+1)-sb.charAt(i);
sb.insert(i+1,c);
}
System.out.print(sb);
}
}