请问此段程序中将提示用户输入Y代表是N代表否后怎么改写程序，谢谢！

Question

package com.imooc;

import java.util.Scanner;

public class GuessBirthday3 {

public static void main(String[] args) {

String set1=

" 1  3  5  7\n"+

" 9 11 13 15\n"+

"17 19 21 23\n"+

"25 27 29 31";

String set2=

" 2  3  6  7\n"+

"10 11 14 15\n"+

"18 19 22 23\n"+

"26 27 30 31";

String set3=

" 4  5  6  7\n"+

"12 13 14 15\n"+

"20 21 22 23\n"+

"28 29 30 31";

String set4=

" 8  9 10 11\n"+

"12 13 14 15\n"+

"24 25 26 27\n"+

"28 29 30 31";

String set5=

"16 17 18 19\n"+

"20 21 22 23\n"+

"24 25 26 27\n"+

"28 29 30 31";

int day=0;

Scanner input=new Scanner(System.in);

System.out.print("Is your birthday in Set1?\n");

System.out.print(set1);

System.out.print("\nEnter 0 for no and 1 for Yes: ");

int answer=input.nextInt();

if(answer==1)

    day+=1;

System.out.print("Is your birthday in Set2?\n");

System.out.print(set2);

System.out.print("\nEnter 0 for No and 1 for Yes: ");

answer=input.nextInt();

if(answer==1)

day+=2;

System.out.print("Is your birthday in Set3?\n");

System.out.print(set3);

System.out.print("\nEnter 0 for No and 1 for Yes: ");

answer=input.nextInt();

if(answer==1)

day+=4;

System.out.print("Is your birthday in Set4?\n");

System.out.print(set4);

System.out.print("\nEnter 0 for No and 1 for Yes: ");

answer=input.nextInt();

if(answer==1)

day+=8;

System.out.print("Is your birthday in Set5\n?");

System.out.print(set5);

System.out.print("\nEnter 0 for No and 1 for Yes: ");

answer=input.nextInt();

if(answer==1)

day+=16;

System.out.println("Your birthday is "+ day +"!");

}

}