#include <iostream>
#include <string>
using namespace std;
int main() {
	int B[10];
	bool Flag[10];
	for (int i = 0; i < 10; i++) {
		Flag[i] = false;
	}
	for (int i = 0; i < 10; i++) {
		cin >> B[i];
	}
	for (int i = 0; i < 10; i++) {
		if(B[i] >= 1 && B[i] <= 9)Flag[B[i]] = true;
		if (B[i] == 10)Flag[0] = true;
	}
	for (int i = 0; i < 10; i++) {
		if (Flag[i] == false) {
			cout << i << endl;
		}
	}
	return 0;
}