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#include <iostream>

using namespace std;

int main() {    
    ios_base::sync_with_stdio(0);
    cin.tie(0);

    int n;
    cin >> n;

    int a;
    int ones_count = 0;
    for( int i=0 ; i<n ; i++ ) {
        cin >> a;
        if( a==1 ) {
            ones_count++;
        }
    }
    
    if( ones_count==0 ) {
        cout << "2" << endl;
    } else if( ones_count==1 ) {
        cout << "1" << endl;
    } else {
        cout << "0" << endl;
    }

    cout << "2" << endl;
    cout << "1 2" << endl;

    return 0;
}