Help me in solving WATERCOOLER2 problem

My issue

My code

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

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

/* Name of the class has to be "Main" only if the class is public. */
class Codechef
{
	public static void main (String[] args) throws java.lang.Exception
	{
		// your code goes here
		Scanner sc =new Scanner (System.in);
		int T =sc.nextInt();
		for (int i=0;i<T;i++){
		    int X=sc.nextInt();
		    int Y=sc.nextInt();
		    int rent=X*5;
		    if (Y==X){
		        System.out.println("0");
		    }
		}
		
		
	}
}

Problem Link: WATERCOOLER2 Problem - CodeChef

The logic I came up with is to divide the cost of the cooler by the number of days and then check if the remainder*rent is less than the cost or not. If it’s not then print the remainder-1.

int rent = sc.nextInt();
int cost = sc.nextInt();
int a = cost/rent;  //remainder

if(a*rent<cost){
    System.out.println(a);
}
else{
    System.out.println(a-1);
}

My solution.