import java.util.Scanner;
import java.util.stream.IntStream;

public class No0481 {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int sum = IntStream.rangeClosed(1, 10).sum();// 1から10までの合計
		int num = sc.nextInt();//書いた数9個の合計

		while (sc.hasNext()) {
			num += sc.nextInt();
		}

		System.out.println(sum - num);
	}
}