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#include<iostream>
using namespace std;
int n, ilosc, x;
int main(){
    ios_base::sync_with_stdio(0);
     cin >> n;
     for(int i = 1; i <= n; i++){
        cin >> x;
        if(x == 1) ilosc++;
     }
     if(ilosc > 1)
        cout << 0 << endl;
     else if(ilosc == 1)
        cout << 1 << endl;
     else cout << 2 << endl;
    cout << 2 << endl;
    cout << 1 << " " << 2;
}