В чем проблема???
package com.javarush.task.task04.task0417;
/*
Существует ли пара?
*/
import java.io.BufferedReader;
import java.io.InputStreamReader;
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 ) {
System.out.print(a + " " + b + " " + c);
}
if (a == b) {
System.out.print(a + " " + b);
}
if (b == c) {
System.out.print(b + " " + c);
}
if (c == a) {
System.out.print(c + " " + a);
}
}
}