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#include <iostream>
using namespace std;
int main()
{ios_base::sync_with_stdio(0);
    int n;
    cin >> n;
int a=0,b;
while(n--){
    cin>>b;
    if(b==1)a++;
}
if(a>1){
    cout<<0<<endl;
    cout<<2<<endl;
    cout<<1<<" "<<2<<endl;
}
else if(a==1){
    cout<<1<<endl;
    cout<<2<<endl;
    cout<<1<<" "<<2<<endl;
}
else{
    cout<<2<<endl;
    cout<<2<<endl;
    cout<<1<<" "<<2<<endl;
}

}