Ну что ему не нравится....
package com.javarush.task.task08.task0828;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.*;
/*
Номер месяца
*/
public class Solution {
public static void main(String[] args) throws IOException {
Map<String, Integer> map = new HashMap<>();
map.put("January",1);
map.put("February",2);
map.put("March",3);
map.put("April",4);
map.put("May",5);
map.put("June",6);
map.put("Jule",7);
map.put("August",8);
map.put("September",9);
map.put("October",10);
map.put("November",11);
map.put("December",12);
Iterator<Map.Entry<String, Integer>> iterator = map.entrySet().iterator();
BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
String s = reader.readLine();
while (iterator.hasNext()) {
Map.Entry<String, Integer> pair = iterator.next();
String key = pair.getKey();
Integer value = pair.getValue();
if (s.equals(key)) {
System.out.println(key+" is the "+value+" month");
}
}
}
}