/* package whatever; // don't place package name! */
 
import java.util.*;
import java.lang.*;
import java.io.*;
 
/* Name of the class has to be "Main" only if the class is public. */
class Ideone
{
 
    public static String blowup(String str) {
        StringBuilder sb = new StringBuilder();
        int repeat = 0;
        for (char c : str.toCharArray()) {
            if (Character.isDigit(c)) {
                repeat = repeat * 10 + Character.getNumericValue(c);
            } else {
                while (repeat > 0) {
                    sb.append(c);
                    repeat--;
                }
                sb.append(c);
            }
        }
        return sb.toString();
    }
 
	public static void main (String[] args) throws java.lang.Exception
	{
		System.out.println(blowup("a3tx23z"));
	}
}

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