public static void bonAppetit(List<Integer> bill, int k, int b) {
    int supposedSum = 0;
    for(int i=0;i<bill.size();i++) {
        if(i!=k) supposedSum += bill.get(i);
    }
    int supposedPaid = supposedSum/2;
    if(supposedPaid == b) System.out.println("Bon Appetit");
    else {
        int toRefund = b-supposedPaid;
        System.out.println(toRefund);
    }
}