import java.util.*;
import java.lang.*;
import java.io.*;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.concurrent.TimeUnit;


// The main method must be in a class named "Main".
class Main {
    public static void main(String[] args) throws ParseException{
        SimpleDateFormat myFormat = new SimpleDateFormat("yyyyMMdd");
        String inputString1 = "20210131";
        String inputString2 = "20210225";

        Date date1 = myFormat.parse(inputString1);
        Date date2 = myFormat.parse(inputString2);
        long diff = date2.getTime() - date1.getTime();
        System.out.println ("Days: " + TimeUnit.DAYS.convert(diff, TimeUnit.MILLISECONDS));
    }
}