#include <bits/stdc++.h>
//#include <atcoder/all>

using namespace std;
//using namespace atcoder;

using ll = long long;
using vll = vector<ll>;
using vvll = vector<vll>;
using pll = pair<ll, ll>;
using vpll = vector<pll>;
using ld = long double;
using vld = vector<ld>;
using vb = vector<bool>;

#define rep(i, n) for (ll i = 0; i < (n); i++)
#ifdef LOCAL
#define dbg(x) cerr << __LINE__ << " : " << #x << " = " << (x) << endl
#else
#define dbg(x) true
#endif

template <class T> bool chmin(T& a, T b) {
    if(a > b) { a = b; return true; }
    else return false;
}

template <class T> bool chmax(T& a, T b) {
    if(a < b) { a = b; return true; }
    else return false;
}

template <class T> ostream& operator<<(ostream& s, const vector<T>& a) {
    for(auto i : a) s << i << ' ';
    return s;
}

constexpr int INF = 1 << 30;
constexpr ll INFL = 1LL << 62;
constexpr ld EPS = 1e-12;
ld PI = acos(-1.0);

void solve() {
    ll n, m;
    cin >> n >> m;
    vll cnt(1001);
    rep(_, n) {
        ll a;
        cin >> a;
        ++cnt[a];
    }
    rep(_, m) {
        ll b;
        cin >> b;
        ++cnt[b];
    }
    for(ll i = 1; i <= 1000; ++i) {
        if(cnt[i] == 1) cout << i << ' ';
    }
    cout << endl;
    return;
}

int main() {
    std::cin.tie(nullptr);
    std::ios_base::sync_with_stdio(false);
    cout << fixed << setprecision(15);
    solve();
}
/*ver 7*/
#include <bits/stdc++.h>
using namespace std;
void init() {cin.tie(0);ios::sync_with_stdio(false);cout << fixed << setprecision(15);}
using ll = long long;
using ld = long double;
using vl = vector<ll>;
using vd = vector<ld>;
using vs = vector<string>;
using vb = vector<bool>;
using vvl = vector<vector<ll>>;
using vvd = vector<vector<ld>>;
using vvs = vector<vector<string>>;
using vvb = vector<vector<bool>>;
using pll = pair<ll,ll>;
using mll = map<ll,ll>;
template<class T> using V = vector<T>;
template<class T> using VV = vector<vector<T>>;
#define each(x,v) for(auto& x : v)
#define reps(i,a,b) for(ll i=(ll)a;i<(ll)b;i++)
#define rep(i,n) for(ll i=0;i<(ll)n;i++)
#define pb push_back
#define eb emplace_back
#define fi first
#define se second
#define mp make_pair
const ll INF = 1LL << 60;
#define CLR(mat,f) memset(mat, f, sizeof(mat))
#define IN(a, b, x) (a<=x&&x<=b)
#define UNIQUE(v) v.erase( unique(v.begin(), v.end()), v.end() ) //被り削除
#define debug cout << "line : " << __LINE__ << " debug" << endl;
#define ini(...) int __VA_ARGS__; in(__VA_ARGS__)
#define inl(...) long long __VA_ARGS__; in(__VA_ARGS__)
#define ind(...) long double __VA_ARGS__; in(__VA_ARGS__)
#define ins(...) string __VA_ARGS__; in(__VA_ARGS__)
#define inc(...) char __VA_ARGS__; in(__VA_ARGS__)
void in(){}
template <typename T,class... U> void in(T &t,U &...u){ cin >> t; in(u...);}
template <typename T> void in1(T &s) {rep(i,s.size()){in(s[i]);}}
template <typename T> void in2(T &s,T &t) {rep(i,s.size()){in(s[i],t[i]);}}
template <typename T> void in3(T &s,T &t,T &u) {rep(i,s.size()){in(s[i],t[i],u[i]);}}
template <typename T> void in4(T &s,T &t,T &u,T &v) {rep(i,s.size()){in(s[i],t[i],u[i],v[i]);}}
template <typename T> void in5(T &s,T &t,T &u,T &v,T &w) {rep(i,s.size()){in(s[i],t[i],u[i],v[i],w[i]);}}
void out(){cout << endl;}
template <typename T,class... U> void out(const T &t,const U &...u){cout << t; if(sizeof...(u)) cout << " "; out(u...);}
void die(){cout << endl;exit(0);}
template <typename T,class... U> void die(const T &t,const U &...u){cout << t; if(sizeof...(u)) cout << " "; die(u...);}
template <typename T> void outv(T s) {rep(i,s.size()){if(i!=0)cout<<" ";cout<<s[i];}cout<<endl;}
template <typename T> void out1(T s) {rep(i,s.size()){out(s[i]);}}
template <typename T> void out2(T s,T t) {rep(i,s.size()){out(s[i],t[i]);}}
template <typename T> void out3(T s,T t,T u) {rep(i,s.size()){out(s[i],t[i],u[i]);}}
template <typename T> void out4(T s,T t,T u,T v) {rep(i,s.size()){out(s[i],t[i],u[i],v[i]);}}
template <typename T> void out5(T s,T t,T u,T v,T w) {rep(i,s.size()){out(s[i],t[i],u[i],v[i],w[i]);}}
#define all(v) (v).begin(),(v).end()
#define rall(v) (v).rbegin(),(v).rend()
template <typename T> T allSum(vector<T> a){T ans=T();each(it,a)ans+=it;return ans;}
ll ceilDiv(ll a,ll b) {return (a+b-1)/b;}
ld dist(pair<ld,ld> a, pair<ld,ld> b){return sqrt(abs(a.fi-b.fi)*abs(a.fi-b.fi)+abs(a.se-b.se)*abs(a.se-b.se));} // ２点間の距離 
ll gcd(ll a, ll b) { return b != 0 ? gcd(b, a % b) : a; }
ll lcm(ll a,ll b){ return a / gcd(a,b) * b;}
template <class A, class B> inline bool chmax(A &a, const B &b) { return b > a && (a = b, true); }
template <class A, class B> inline bool chmin(A &a, const B &b) { return b < a && (a = b, true); }
#define YES(n) ((n) ? "YES" : "NO"  )
#define Yes(n) ((n) ? "Yes" : "No"  )
#define yes(n) ((n) ? "yes" : "no"  )

int main(){
  init();
  inl(n,m);
  V<ll> a(n),b(m);
  in1(a);
  in1(b);
  set<ll> A,B;
  rep(i,n)A.insert(a[i]);
  rep(i,m)B.insert(b[i]);
  reps(i,1,1001){
    ll af=A.count(i);
    ll bf=B.count(i);
    if(af+bf==1)out(i);
  }
  return 0;
}