import java.util.Scanner;

public class SequencesofEqualStrings {
	public static void main(String[] args) {
		Scanner str = new Scanner(System.in);
		String input = str.nextLine();
		String[] words = input.split(" ");
		if (words.length == 1) {
			System.out.println(words[0]);
		}
		for (int i = 0; i < words.length - 1; i++) {
			if (words[i].equals(words[i + 1])) {
				System.out.print(words[i] + " ");

			} else {
				System.out.println(words[i]);
			}
		}
		if (words.length != 1) {
			System.out.print(words[words.length - 1]);
		}
	}
}