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#include<iostream>
#include<vector>

using namespace std;

int main()
{
    ios_base::sync_with_stdio(false);
    int n,x;
    cin >>n;

    int counter=0;
    for(int i=0; i<n; i++)
    {
        cin >>x;
        if(x==1)
        {   
            counter++;
        }
    }
    cout<<2-min(counter,2)<<"\n2\n1 2\n";

    return 0;
}