Вроде все норм.
package com.javarush.task.task04.task0417;
/*
Существует ли пара?
*/
import java.io.*;
import java.util.*;
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==c & a==c){
System.out.print(a+" "+" "+b+" "+c);
}
if (b==c){
System.out.print(b+" "+c);
}
if (a==c){
System.out.print(a+" "+c);
}
if (b==a){
System.out.print(a+" "+b);
}
else if (b==a ){
System.out.print(a+" "+b);
}
}}