import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        final Scanner scanner = new Scanner(System.in);
        String in = scanner.nextLine();
        in = in.substring(0, in.length() - 1);
        final String[] sentence = in.split(" ");
        String best = sentence[0];
        int max = 0;
        for (String word : sentence) {
            int length = word.length();
            if (length <= max) continue;
            max = length;
            best = word;
        }
        System.out.println(best);
    }
}