#include<bits/stdc++.h>
#define rep(i,a,b) for(int i=a;i<b;i++)
#define rrep(i,a,b) for(int i=a;i>=b;i--)
#define fore(i,a) for(auto &i:a)
#define all(x) (x).begin(),(x).end()
//#pragma GCC optimize ("-O3")
using namespace std;
void _main(); int main() { cin.tie(0); ios::sync_with_stdio(false); _main(); }
typedef long long ll; const int inf = INT_MAX / 2; const ll infl = 1LL << 60;
template<class T>bool chmax(T& a, const T& b) { if (a < b) { a = b; return 1; } return 0; }
template<class T>bool chmin(T& a, const T& b) { if (b < a) { a = b; return 1; } return 0; }
//---------------------------------------------------------------------------------------------------
/*---------------------------------------------------------------------------------------------------
　　　　　　　　　　　 ∧＿∧
　　　　　 ∧＿∧ 　（´<_｀ ）　 Welcome to My Coding Space!
　　　　 （ ´_ゝ`）　/　 ⌒i     @hamayanhamayan0
　　　　／　　　＼　 　  |　|
　　　 /　　 /￣￣￣￣/　　|
　 ＿_(__ﾆつ/　    ＿/ .| .|＿＿＿＿
　 　　　＼/＿＿＿＿/　（u　⊃
---------------------------------------------------------------------------------------------------*/














int N, M, A[1010], B[1010];
//---------------------------------------------------------------------------------------------------
void _main() {
	cin >> N >> M;
	rep(i, 0, N) cin >> A[i];
	rep(i, 0, M) cin >> B[i];

	map<int, int> cnt;
	rep(i, 0, N) cnt[A[i]]++;
	rep(i, 0, M) cnt[B[i]]++;

	bool top = true;
	fore(p, cnt) if (p.second == 1) {
		if (!top) printf(" ");
		printf("%d", p.first);
		top = false;
	}
	printf("\n");
}






#include <bits/stdc++.h>
#define rep(i, n) for (lli i = 0; i < (n); i++)
#define rrep(i, n) for (lli i = (n)-1; i >= 0; i--)
#define vall(x) (x).begin(), (x).end()
using namespace std;
namespace atcoder {}
using namespace atcoder;
using lli = long long int;
void YESNO(bool), YesNo(bool);
template <class T1, class T2> bool chmin(T1 &l, const T2 &r);
template <class T1, class T2> bool chmax(T1 &l, const T2 &r);
#define int long long int

void solve(long long N, long long M, std::vector<long long> A,
           std::vector<long long> B) {
  vector<int> count(10000);
  for (auto c : A)
    count[c]++;
  for (auto c : B)
    count[c]++;
  rep(i, 10000) {
    if (count[i] == 1) {
      cout << i << " ";
    }
  }
}

signed main() {
  long long N;
  scanf("%lld", &N);
  long long M;
  scanf("%lld", &M);
  std::vector<long long> A(N);
  for (int i = 0; i < N; i++) {
    scanf("%lld", &A[i]);
  }
  std::vector<long long> B(M);
  for (int i = 0; i < M; i++) {
    scanf("%lld", &B[i]);
  }
  solve(N, M, std::move(A), std::move(B));
  return 0;
}

// -- lib
void YESNO(bool b) { cout << (b ? "YES" : "NO") << endl; }
void YesNo(bool b) { cout << (b ? "Yes" : "No") << endl; }

template <class T1, class T2> bool chmin(T1 &l, const T2 &r) {
  return (l > r) ? (l = r, true) : false;
}

template <class T1, class T2> bool chmax(T1 &l, const T2 &r) {
  return (l < r) ? (l = r, true) : false;
}

template <class T1, class T2> void vadd(vector<T1> &v, T2 x) {
  for (auto &s : v)
    s += T2(x);
}
