#include <bits/stdc++.h>

using namespace std;
using ll = long long;

int main()
{
    ll m, s;
    cin >> m >> s;
    vector<vector<vector<ll>>> z1(m, vector<vector<ll>>(s));
    for (int i = 0; i < m; i++)
    {
        ll a;
        cin >> a;
        z1.at(i).at(0).push_back(a);
        for (int j = 1; j < s; j++)
        {
            cin >> a;
            z1.at(i).at(j) = z1.at(i).at(j - 1);
            z1.at(i).at(j).push_back(a);
            sort(z1.at(i).at(j).begin(), z1.at(i).at(j).end());
        }
    }
    ll c1;
    for (int i = 0; i < s; i++)
    {
        bool xd = true;
        for (int j = 0; j < m - 1; j++)
        {
            if (z1.at(j).at(i) != z1.at(j + 1).at(i))
            {
                xd = false;
                break;
            }
        }
        if (xd == true)
        {
            c1 = i;
            break;
        }
    }
    ll s1z = z1.at(0).at(c1).size();
    cout << s1z << endl;
    for (int i = 0; i < s1z; i++)
    {
        cout << z1.at(0).at(c1).at(i) << " ";
    }
    cout << endl;
    return 0;
}