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#include <bits/stdc++.h>
using namespace std;

int n,x,j;

int main()
{
    cin>>n;
    for( n ; n>0 ; --n )
    {
        cin>>x;
        if(x==1) ++j;
    }

    if(j>=2) cout<<"0"<<endl;
    else if(j==1) cout<<"1"<<endl;
    else cout<<"2"<<endl;

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