#include <fstream>

#include <iostream>

using namespace std;

int main()

{

	fstream f;

	int n, i, max = 0, aux, k = 0, v[1001], vback[1001], a[1001], j, poz, s;

	bool x[50001] = {}, cont, bun;

	f.open("economie.in", ios::in);

	f >> n;

	//citim

	for (i = 0; i < n; ++i) {

		f >> aux;

		if ( aux > max ) max = aux;

		x[aux] = true;

	}

	f.close(); //inchis fisier

	//sortam

	++max;

	for (i = 1; i < max; ++i)

		if ( x[i] ) v[++k] = i;

	f.open("economie.out", ios::out);

	if (v[1] == 1) {

		f << "1" << endl << "1" << endl;

		f.close();

		return 0;

	}

	//incepem

	k = 1; //cate elemente avem in a

	a[1] = v[1];

	for (i = 2; i <= n; ++i) {

		cont = false;

		//mai intai verifivam cu impartirea

		for (j = k; j > 0; --j)

			if ( !(v[i] % a[j]) ) {

				cont = true;

				break;

			}

		if (cont) continue;

		if (k == 1) {

			a[++k] = v[i];

			continue;

		}

		//apoi cu 2 numere

		if (k == 2) {

			cont = true;

			aux = v[i];

			while (aux > 0) {

				aux -= a[2];

				if ( !(aux % a[1]) ) {

					cont = false;

					break;

				}

			}

			if (cont) a[++k] = v[i];

			continue;

		}

		//acuma backtrack si atata

		cont = true;

		poz = 1;

		vback[poz] = -1;

		while (poz > 0) {

			bun = false;

			++vback[poz];

			//verificare

			s = 0;

			for (j = 1; j <= poz; ++j)

				s += vback[j] * a[j];

			if (s <= v[i]) bun = true;

			if (!bun) --poz;

			else if (poz == k) {

				s = v[i] - s;

				for (j = 1; j <= k; ++j)

					if ( !(s % a[j]) ) {

						cont = false;

						poz = -1;

						break;

					}

			}

			else {

				++poz;

				vback[poz] = -1;

			}

		}

		if ( cont ) a[++k] = v[i];

	}

	f << k << endl;

	for (i = 1; i <= k; ++i) {

		f << a[i] << endl;

	}

	f.close();

	return 0;

}