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#include <bits/stdc++.h>

using namespace std;

void initialize()
{
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
}

int main()
{
    initialize();

    int n;
    cin >> n;
    int one_count = 0;
    for (auto i = 0; i < n; i++)
    {
        int x;
        cin >> x;
        if (x == 1)
            one_count++;
    }

    cout << max(2 - one_count, 0) << "\n2\n1 2\n";

    return 0;
}