import java.util.regex.Matcher;
import java.util.regex.Pattern;
 
 
/* Name of the class has to be "Main" only if the class is public. */
class Test
{
    public static void main (String[] args) throws java.lang.Exception
    {
        Pattern pat= Pattern.compile("\\G([0-9]++)([^0-9])");
        String text= "5x12e";
        StringBuilder result= new StringBuilder();
        Matcher match= pat.matcher(text);
        while ( match.find() ) {
            for (int i=0; i<Integer.parseInt(match.group(1)); i++) {
                result.append(match.group(2));
            }
        }
        System.out.println(result);
    }
 
}
 

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