Kevin-Avo

#include <bits/stdc++.h>
#define endl '\n'
#define DV(value) cout << "[" << value << "]";
#define DPI(p) cout << "[" << p.first << "," << p.second << "]";
#define MAX 10000

using namespace std;

typedef pair<int,int> pii;

struct Comp {
    // important: we need two overloads, because the comparison
    // needs to be done both ways to check for equality

    bool operator()(pii p, int s) const
    { return p.first < s; }
    bool operator()(int s, pii p) const
    { return s < p.first; }
};

struct cmp
{
    bool operator() ( const pii &a, const pii &b) const {
        if(a.second > b.second) return true;
        else if(a.second < b.second) return false;
        else return a.first < b.first;
    }
};

int main()
{
    int N,M;

    while(cin >> N >> M and N != 0 and M != 0)
    {
        unordered_map<int,int> aparicoes;

        for(int i = 0; i < N;i++)
        {
            for(int j = 0; j < M;j++)
            {
                int id;
                cin >> id;
                auto it = aparicoes.find(id);

                if(it != aparicoes.end())
                    aparicoes[id] = aparicoes[id] + 1;
                else
                    aparicoes[id] = 0;
            }
        }

        set<pii,cmp> apar_ord;

        for(auto item : aparicoes)
        {
            apar_ord.insert( item );
        }
       
	int value = apar_ord.begin()->second;

	auto it = apar_ord.begin();

	while(it != apar_ord.end() and value == it->second) it++;

	value = it->second;
	
	while(it != apar_ord.end() and value == it->second)
	{
	    cout << it->first << " ";
	    it++;
	}

	cout << endl;
    }
}