Что не так? ВОТ ЧТО?
package com.javarush.task.task04.task0417;
/*
Существует ли пара?
*/
import java.io.*;
public class Solution {
public static void main(String[] args) throws Exception {
BufferedReader reader = new BufferedReader (new InputStreamReader(System.in));
int a = Integer.parseInt(reader.readLine());
int b = Integer.parseInt(reader.readLine());
int c = Integer.parseInt(reader.readLine());
if (a == b || b == a) {
System.out.print(a + " " + b);
} else if (a == c || c == a) {
System.out.print(a + " " + c);
} else if (b == c || c == b) {
System.out.print (b + " " + c);
} else if (a == b && a == c) {
System.out.print(a + " " + a + " " + a);
}
}
}