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#include <bits/stdc++.h>

using namespace std;

int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr); cout.tie(nullptr);

    int n, a, c1 = 0;

    cin >> n;
    for (int i = 0; i < n; ++i) {
        cin >> a;
        if (a == 1) ++c1;
    }
    cout << max(2-c1, 0) << "\n2\n1 2\n";

    return 0;
}