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#include<iostream>

using namespace std;

int n, t[1000007], x=2;

int main()
{
    ios_base::sync_with_stdio(0);
    cin>> n;
    for(int i=0; i<n; i++)
    {
        cin>> t[i];
        if(t[i]==1)
        {
            x--;
        }
        if(x==0)
        {
            break;
        }
    }
    cout<< x << endl;
    cout<< 2 << endl;
    cout<< 1 << " " << 2 << endl;
}