#include<iostream>
#include<string>
#include<string.h>
#include<algorithm>
#include<stdio.h>
#include<cmath>
#include<vector>
#include<utility>
#define FOR(i, a, b) for(int i=(a);i<=(b);i++)
#define RFOR(i, a, b) for(int i=(a);i>=(b);i--)
#define MOD 1000000007

using namespace std;


int main(void) {
	int a[10];
	int dp[11] = {};
	FOR(i, 0, 8) {
		cin >> a[i];
	}
	FOR(i, 0, 8) {
		FOR(t, 1, 10) {
			if (a[i] == t) {
				dp[t] = 1;
			}
		}
	}
	FOR(i, 1, 10) {
		if (dp[i] == 0) {
			cout << i << endl;
		}
	}
	return 0;
}