/* package whatever; // don't place package name! */

import java.util.*;
import java.lang.*;
import java.io.*;

import java.time.* ;
import java.time.format.* ;

/* Name of the class has to be "Main" only if the class is public. */
class Ideone
{
	public static void main (String[] args) throws java.lang.Exception
	{

        String original = "2017042er7" ;
        String input = original.replaceAll( "\\D+" , "" ) ;
        LocalDate ld = LocalDate.parse( input , DateTimeFormatter.BASIC_ISO_DATE ) ;
    
        System.out.println( "original: " + original ) ;
        System.out.println( "ld.toString(): " + ld ) ;
	}
}