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#include <iostream>
using namespace std;

int main() {
    ios_base::sync_with_stdio(0);
    int n;
    cin >> n;
    int cnt1 = 0;
    for(int i=0; i<n; i++) {
        int a;
        cin >> a;
        if (a == 1)
            cnt1 += 1;
    }
    if (cnt1 >= 2)
        cout << "0" << endl;
    else if(cnt1 == 1)
        cout << "1" << endl;
    else
        cout << "2" << endl;

    cout << "2\n1 2" << endl;
    return 0;
}