// Source: https://usaco.guide/general/io

#include <bits/stdc++.h>
using namespace std;

int main() {
	int n, sor = 0;
	cin >> n;
	string elem = "";
	for (int i = 0; i < n; i++) {
		int a;
		cin >> a;
		if (a == 0) {
			sor++;
			elem += "0";
		}
		if (a == 1) {
			sor++;
			elem += "1";
		}
		if (a == 2) {
			sor++;
			elem += "2";
		}
		if (a == 3) {
			sor--;
			elem.pop_back();
		}
		if (a == 4) {
			int j = elem.size() - 1;
			while (elem[j] == '0') {
				elem[j] = '2';
				j--;
			}
			elem[j]--;
		}
		if (a == 5) {
			int j = elem.size() - 1;
			while (elem[j] == '2') {
				elem[j] = '0';
				j--;
			}
			elem[j]++;
		}
	}

	cout << sor << "\n";
	if (elem == "") cout << "0";
	else cout << elem;
}