Can someone explain to me what this code is trying to do?

import java.util.*; public class Main { public static void main(String[] args) { Scanner sc= new Scanner(System.in); ArrayList first = new ArrayList<>(); // To store trainer who enrolled 0-5 members ArrayList second = new ArrayList<>(); // To store trainer who enrolled 6-12 members ArrayList third = new ArrayList<>(); // To store trainer who enrolled 13-20 members ArrayList fourth = new ArrayList<>(); // To store trainer who enrolled more than 20 members for(int i=0 ;i<=25;i++) { String name=sc.next(); int nw=sc.nextInt(); if(nw >=0 && nw<=5) first.add(name); else if(nw<=12) second.add(name); else if(nw<=20) third.add(name); else fourth.add(name); } System.out.println("Trainers who enrolled 0-5 new members :"); for(int i=0;i