Why not? Вывод то, что нужно, да и логику решения взял из лекции JAVARUSH

package com.javarush.task.task08.task0823; import java.io.BufferedReader; import java.io.IOException; import java.io.InputStreamReader; public class Solution { public static void main(String[] args) throws IOException { BufferedReader reader = new BufferedReader(new InputStreamReader(System.in)); String a = reader.readLine(); String b = reader.readLine(); String c = reader.readLine(); String merge = (a + " " + b + " " + c); char[] chars = merge.toCharArray(); for (int i = 0; i < chars.length; i++) { if (i == 0 || chars[i - 1] == ' ') { chars [i] = Character.toUpperCase(chars[i]); } } System.out.println(new String(chars)); } }