import java.util.Scanner;
import java.util.Arrays;

public class Main {
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);

		String[] array = new String[3];
		for(int i = 0; i < 3; i++){
			array[i] = sc.next();
		}

		Arrays.sort(array);

		System.out.println(array[1]);
	}
}