Go: package main

import (
	"bufio"
	"fmt"
	"os"
	"sort"
	"strconv"
)

func main() {
	var n, m int
	fmt.Scan(&n, &m)

	mm := make(map[int]bool)
	am := make(map[int]bool)
	om := make(map[int]bool)

	var sc = bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)

	for i := 0; i < n; i++ {
		sc.Scan()
		a, _ := strconv.Atoi(sc.Text())
		mm[a] = true
		om[a] = true
	}
	for i := 0; i < m; i++ {
		sc.Scan()
		b, _ := strconv.Atoi(sc.Text())
		if bl, ok := mm[b]; ok && bl {
			am[b] = true
		}
		om[b] = true
	}
	fmt.Printf("%d %d\n", len(am), len(om))
	as := make([]int, 0)
	for k := range am {
		as = append(as, k)
	}
	sort.Sort(sort.IntSlice(as))
	os := make([]int, 0)
	for k := range om {
		os = append(os, k)
	}
	sort.Sort(sort.IntSlice(os))
	for i := range as {
		fmt.Println(as[i])
	}
	for i := range os {
		fmt.Println(os[i])
	}
}

C++: #include<iostream>
#include<algorithm>
#include<cstdio>
#include<cmath>
#include<cctype>
#include<math.h>
#include<string>
#include<string.h>
#include<stack>
#include<queue>
#include<vector>
#include<utility>
#include<set>
#include<map>
#include<stdlib.h>
#include<iomanip>

using namespace std;

#define ll long long
#define ld long double
#define EPS 0.0000000001
#define INF 1e9
#define LINF (ll)INF*INF
#define MOD 1000000007
#define rep(i,n) for(int i=0;i<(n);i++)
#define loop(i,a,n) for(int i=a;i<(n);i++)
#define all(in) in.begin(),in.end()
#define shosu(x) fixed<<setprecision(x)

#define int ll //!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

typedef vector<int> vi;
typedef vector<string> vs;
typedef pair<int,int> pii;
typedef vector<pii> vp;

int gcd(int a, int b){
    if(b==0) return a;
    return gcd(b,a%b);
}
int lcm(int a, int b){
    return a/gcd(a,b)*b;
}


signed main(void) {
    int n,m;
    cin >> n >> m;
    vi a(n),b(m);
    rep(i,n) cin >> a[i];
    rep(i,m) cin >> b[i];
    sort(all(a));
    sort(all(b));
    map<int,int> ma;
    ma[a[0]]++;
    ma[b[0]]++;
    rep(i,n-1)if(a[i+1] != a[i])ma[a[i+1]]++;
    rep(i,m-1)if(b[i+1] != b[i])ma[b[i+1]]++;
    vi v1,v2;
    for(auto itr = ma.begin(); itr != ma.end(); itr++){
        int cnt = itr->second;
        //cout << (itr->first) << " " << cnt << endl;
        if(cnt > 1)v1.push_back(itr->first);
        v2.push_back(itr->first);
    }
    cout << v1.size() << " " << v2.size() << endl;
    sort(all(v1));
    sort(all(v2));
    rep(i,v1.size())cout << v1[i] << endl;
    rep(i,v2.size())cout << v2[i] << endl;
}

C++: #include <bits/stdc++.h>
#define trace1(x)                cout<<#x<<": "<<x<<endl
#define trace2(x, y)             cout<<#x<<": "<<x<<" | "<<#y<<": "<<y<<endl
#define trace3(x, y, z)          cout<<#x<<":" <<x<<" | "<<#y<<": "<<y<<" | "<<#z<<": "<<z<<endl
#define trace4(a, b, c, d)       cout<<#a<<": "<<a<<" | "<<#b<<": "<<b<<" | "<<#c<<": "<<c<<" | "<<#d<<": "<<d<<endl
#define trace5(a, b, c, d, e)    cout<<#a<<": "<<a<<" | "<<#b<<": "<<b<<" | "<<#c<<": "<<c<<" | "<<#d<<": "<<d<<" | "<<#e<< ": "<<e<<endl
#define trace6(a, b, c, d, e, f) cout<<#a<<": "<<a<<" | "<<#b<<": "<<b<<" | "<<#c<<": "<<c<<" | "<<#d<<": "<<d<<" | "<<#e<< ": "<<e<<" | "<<#f<<": "<<f<<endl
#define trace7(a, b, c, d, e, f , g) cout<<#a<<": "<<a<<" | "<<#b<<": "<<b<<" | "<<#c<<": "<<c<<" | "<<#d<<": "<<d<<" | "<<#e<< ": "<<e<<" | "<<#f<<": "<< f << " | "<< #g <<": "<<g<<endl
#define trace8(a, b, c, d, e, f , g , h) cout<<#a<<": "<<a<<" | "<<#b<<": "<<b<<" | "<<#c<<": "<<c<<" | "<<#d<<": "<<d<<" | "<<#e<< ": "<<e<<" | "<<#f<<": "<< f << " | " << #g <<": "<< g <<" | "<<#h<< ": " << h << endl
#define rep(i,a,b) for(int i=(int)(a);i<(int)(b);++i)
#define rrep(i,a,b) for(int i=(int)(a);i>=(int)(b);--i)
#define fore(x,a) for(auto &x:a)
#define all(a) (a).begin(),(a).end()
#define rall(a) (a).rbegin(),(a).rend()
#define isin(i,a,b) ((a) <= (i) && (i) <= (b))
#define uni(a) (a).erase(unique(all(a)),(a).end())
#define dup(x,y) (((x)+(y)-1)/(y))
#define fi first
#define se second
#define pb push_back
#define eb emplace_back
#define sz(a) ((long long)(a).size())
#define v(T) vector<T>
#define vv(T) v(v(T))
using namespace std;
using ll  = long long;          using vi  = vector<int>;
using unit= unsigned;           using vl  = vector<ll>;
using ull = unsigned long long; using vvi = vector<vi>;
using P   = pair<int,int>;      using vvl = vector<vl>;
                                using vp  = vector<P>;
void _main(); int main(){ cin.tie(0); ios::sync_with_stdio(false); _main(); }
template<class T>string join(const v(T)&v){ stringstream s; rep(i,0,sz(v))s<<' '<<v[i]; return s.str().substr(1); }
template<class T>istream &operator>>(istream&i, v(T)&v){ fore(x,v){ i >> v; } return i; }
template<class T>ostream &operator<<(ostream&o, const v(T)&v){ o<<"["; fore(x,v)o<<x<<","; o<<"]"; return o; }
template<class T>ostream &operator<<(ostream&o, const deque<T>&v){ o<<"deq["; fore(x,v)o<<x<<","; o<<"]"; return o; }
template<class T>ostream &operator<<(ostream&o, const set<T>&v){ o<<"{"; fore(x,v)o<<x<<","; o<<"}"; return o; }
template<class T>ostream &operator<<(ostream&o, const unordered_set<T>&v){ o<<"{"; fore(x,v)o<<x<<","; o<<"}"; return o; }
template<class T>ostream &operator<<(ostream&o, const multiset<T>&v){ o<<"{"; fore(x,v)o<<x<<","; o<<"}"; return o; }
template<class T>ostream &operator<<(ostream&o, const unordered_multiset<T>&v){ o<<"{"; fore(x,v)o<<x<<","; o<<"}"; return o; }
template<class T1,class T2>ostream &operator<<(ostream &o, const pair<T1,T2>&p){ o<<"("<<p.fi<<","<<p.se<<")"; return o; }
template<class TK,class TV>ostream &operator<<(ostream &o, const map<TK,TV>&m){ o<<"{"; fore(x,m)o<<x.fi<<"=>"<<x.se<<","; o<<"}"; return o; }
template<class TK,class TV>ostream &operator<<(ostream &o, const unordered_map<TK,TV>&m){ o<<"{"; fore(x,m)o<<x.fi<<"=>"<<x.se<<","; o<<"}"; return o; }
template<class T>void YES(T c){ if(c) cout<<"YES"<<endl; else cout<<"NO"<<endl; }
template<class T>void Yes(T c){ if(c) cout<<"Yes"<< endl; else cout<<"No"<<endl; }
template<class T>void POSS(T c){ if(c) cout<<"POSSIBLE"<<endl; else cout<<"IMPOSSIBLE"<<endl; }
template<class T>void Poss(T c){ if(c) cout<<"Possible"<<endl; else cout<<"Impossible"<<endl; }
template<class T>void chmax(T &a, const T &b){ if(a<b) a=b; }
template<class T>void chmin(T &a, const T &b){ if(b<a) a=b; }
template<class T>T gcd(T a, T b){ return (b==0) ? a : gcd(b,a%b); }
template<class T>T lcm(T a, T b){ return a * (b / gcd(a,b)); }
const double  EPS = 1e-10;
const double  PI  = acos(-1.0);
const int     INF = 1001002003;
const ll      LINF= 1001002003004005006LL;
const int dx[] = { -1, 0, 1, 0 , -1,-1, 1, 1 };
const int dy[] = {  0, 1, 0,-1 , -1, 1,-1, 1 };

void _main() {
  int N, M;
  cin >> N >> M;
  set<int> ans_or;
  set<int> ans_and;
  rep(i, 0, N) {
    int t; cin >> t;
    ans_or.insert(t);
  }
  rep(i, 0, M) {
    int t; cin >> t;
    if (ans_or.count(t)) ans_and.insert(t);
    ans_or.insert(t);
  }
  cout << sz(ans_and) << " " << sz(ans_or) << endl;
  fore(x, ans_and) cout << x << endl;
  fore(x, ans_or) cout << x << endl;
}

C++: #include <bits/stdc++.h>
using namespace std;
using ll = long long;

int N, K;
vector<int> u, v;

int main()
{
    int n, m;
    cin >> n >> m;
    int a[n], b[m];
    map<int, int> mp;
    map<int, int> mpp;
    for (int i = 0; i < n; i++)
    {
        cin >> a[i];
        mp[a[i]]++;
        mpp[a[i]]++;
        u.push_back(a[i]);
    }
    for (int i = 0; i < m; i++)
    {
        cin >> b[i];
        if (mp[b[i]] == 1)
            v.push_back(b[i]);
        if (mpp[b[i]] == 0)
            u.push_back(b[i]);
    }
    cout << v.size() << " " << u.size() << endl;
    sort(u.begin(), u.end());
    sort(v.begin(), v.end());
    for (int i = 0; i < v.size(); i++)
    {
        cout << v[i] << endl;
    }
    for (int i = 0; i < u.size(); i++)
    {
        cout << u[i] << endl;
    }
    return 0;
}