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

template <typename T> T load() { T r; cin >> r; return r; }
template <typename T> vector<T> loadMany(int n) { vector<T> rs(n); generate(rs.begin(), rs.end(), &load<T>); return rs; }

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    auto n = load<int>();
    auto ones = 0;
    for (auto i=0; i<n; ++i)
        if (load<int>() == 1)
            ++ones;
    cout << max(2 - ones, 0) << "\n2\n1 2\n";
}