Help me in solving AOJ20 problem

help
,
1

My issue

My code

import java.util.*;

class Codechef
{
	public static void main (String[] args)
	{
		Scanner read = new Scanner(System.in);
		int t = read.nextInt();
		for(int i=0; i<t; i++)
		{
		    ArrayList<Integer> a = new ArrayList<Integer>();
		    ArrayList<Integer> b = new ArrayList<Integer>();
		    int n = read.nextInt();
		    for(int j=1; j<=n; j++){
		        int ele = read.nextInt();
    		    a.add(ele);
		    }
		    for(int k=1; k<=n; k++){
		        int ele = read.nextInt();
    		    b.add(ele);
		    }
		    // Update the code below to solve this problem
		     int avail = 0;
		     int need = 0;
		     int count = 0;
		     for(int l=0;l<n;l++){
		         if(l==0){
		             avail = a.get(l);
		             need = b.get(l);
		             if(need <= avail){
		                 count++;
		                 }
		              }
		          else if(l > 0){
		                 avail = a.get(l)-a.get(l-1);
		                 if(b.get(l) < avail){
		                     count++;
		                 }
		             }
		         
		     }
		     System.out.println(count);
		    }
	}
}

Learning course: Java for problem solving - 2
Problem Link: CodeChef: Practical coding for everyone
Can someone point out the flaw in my code? Thanks