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#include <iostream>

using namespace std;

int main() {
    ios_base::sync_with_stdio(false);
    int n;
    cin >> n;
    int ones = 0;
    for (int i = 1; i <= n; i++) {
        int a;
        cin >> a;
        if (a == 1) {
            ones++;
        }
    }
    if (ones >= 2) {
        cout << 0 << '\n';
    }
    else if (ones >= 1) {
        cout << 1 << '\n';
    }
    else {
        cout << 2 << '\n';
    }
    cout << 2 << '\n';
    cout << 1 << ' ' << 2 << '\n';
    return 0;
}