может кавычки нужны?)
package com.javarush.task.task08.task0828;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.HashSet;
import java.util.List;
import java.util.*;
/*
Номер месяца
*/
public class Solution {
public static void main(String[] args) throws IOException {
//напишите тут ваш код
BufferedReader reader= new BufferedReader(new InputStreamReader(System.in));
Map<String,Integer> month =new HashMap<String,Integer>();
month.put("January",1);
month.put("Febuary",2);
month.put("March",3);
month.put("April",4);
month.put("May",5);
month.put("June",6);
month.put("July",7);
month.put("August",8);
month.put("September",9);
month.put("October",10);
month.put("November",11);
month.put("December",12);
String s=reader.readLine();
for (Map.Entry<String, Integer> entry: month.entrySet()){
if (s.equals(entry.getKey())){
System.out.println(s +" is the "+ entry.getValue() + " month.");
}
}
}
}