1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
#include<bits/stdc++.h>

using namespace std;
using i64 = long long;
using i32 = int;

template<typename T> T load() { T x; cin >> x; return x; }
template<typename T> vector<T> loadN(int s) { vector<T> vt(s); for(auto& el : vt) el = load<T>(); return vt; }
template<typename T> ostream& operator<<(ostream& os, const vector<T>& vt) { for(auto& el : vt) os << el << ' '; return os; }

i32 main() {
	ios::sync_with_stdio(false);
	auto seq = loadN<i32>(load<i32>());
	auto counter = 0;
	for(auto& el : seq)
		if(el == 1)
			++counter;
	cout << 2 - min(counter, 2) << '\n';
	cout << "2\n1 2\n";
}