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#include <bits/stdc++.h>

using namespace std;


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

    int n;
    cin>>n;

    int ljed=0;
    for(int i=0; i<n; i++){
        int temp;
        cin>>temp;
        if(temp==1)ljed++;
    }

    if(ljed>=2)cout<<"0\n";
    else if(ljed==1)cout<<"1\n";
    else if(ljed==0)cout<<"2\n";

    cout<<"2\n";
    cout<<"1 2\n";

    return 0;
}