#include <iostream>
#include <cstdio>
#include <cstdlib>
#include <vector>
#include <algorithm>
#include <cmath>
#include <stack>
#include <functional>
#include <set>
#include <queue>
#include <string>
#include <map>
#include <iomanip>
#include <sstream>
#include <cassert>

class Set {
 private:
    std::vector<int64_t> set;
 public:
    Set() = default;
    explicit Set(const std::vector<int64_t>& v) {
        for (int64_t i = 0; i < v.size(); i++) {
            this->Add(v[i]);
        }
    }

    std::vector<int64_t> Data() const {
        return this->set;
    }

    void Add(int64_t num) {
        if (!this->Contains(num)) {
            this->set.push_back(num);
        }
    }

    void Remove(int64_t num) {
        this->set.erase(find(this->set.begin(), this->set.end(), num));
    }

    bool Contains(int64_t num) const {
        return find(this->set.begin(), this->set.end(), num)
        != this->set.end();
    }

    Set Union(const Set& other) const {
        Set s;
        for (int64_t i = 0; i < this->set.size(); i++) {
            s.Add(this->Data()[i]);
        }
        for (int64_t j = 0; j < other.set.size(); j++) {
            s.Add(other.Data()[j]);
        }
        return s;
    }

    Set Intersection(const Set& other) const {
        Set s;
        for (int64_t i = 0; i < other.set.size(); i++) {
            if (this->Contains(other.set[i])) {
                s.Add(other.Data()[i]);
            }
        }
        return s;
    }

    Set Difference(const Set& other) const {
        Set s;
        for (int64_t i = 0; i < this->set.size(); i++) {
            if (!other.Contains(this->Data()[i])) {
                s.Add(this->Data()[i]);
            }
        }
        return s;
    }

    Set SymmetricDifference(const Set& other) const {
        Set s;
        s = this->Difference(other);
        s = s.Union(other.Difference(this->set));
        return s;
    }
};