自动贩卖机的更改制造商-Java

Question

因此，我们的程序假设让用户输入一定数量的钱，然后生成他们得到多少零钱（四分之一，零点等），然后找回零钱后，该程序会要求用户输入是否想要再试一次还是不试。这是该程序似乎无法正常工作的地方，我需要帮助。这是我到目前为止的内容：

package week14;
import java.util.Scanner;
public class VendingMachine {

    public static void main(String[] args) {
    Scanner input = new Scanner(System.in);

    System.out.print("Enter a whole number 1-99.\n I will find a combination of coins\n that equals that amount of change: ");
    int coins = input.nextInt();
    String answer = "yes";
    while (answer.equals("yes")) {
                if (coins >=1 && coins <= 99) {
                    int quarters = coins / 25;
                    int dimes = (coins%25) / 10;
                    int nickels = ((coins%25)%10) / 5;
                    int pennies = (((coins%25)%10)%5) / 1;

                    System.out.print(coins + " cents in coins can be given as\n"+quarters+" quarters\n"+dimes+" dimes\n"+nickels+" nickels\n"+pennies+" pennies\n");
                    System.out.print("Do you want to try again? ");
                    answer = input.nextLine();
                    answer = answer.toLowerCase(); 

                    System.out.print("\nEnter a whole number 1-99.\n I will find a combination of coins\n that equals that amount of change: ");
                    coins = input.nextInt();
                }else {
                    System.out.print("Please enter between 1-99.\nEnter again: ");
                    coins = input.nextInt();
                } 
                if(answer.equals("no")) {
                    System.out.println("\nThanks for using \"Change Maker\" program!");
                    break;
                }

        }
    }
}