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#include<bits/stdc++.h>
using namespace std;
int main()
{
    int n;
    cin>>n;
    int i,a,j=0;
    for (i=0;i<n;i++)
    {
        cin>>a;
        if (a==1) j++;
    }
    if (j>=2)  cout<<"0"<<endl;
    else if (j==1) cout<<"1"<<endl;
    else cout<<"2"<<endl;
    cout<<"2"<<endl;
    cout<<"1 2"<<endl;
}