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#include <iostream>
using namespace std;
int main() {
    int n, s = 0, i, a;
    cin >> n;
    for(i = 0; i < n; i++) {
        cin >> a;
        if(a == 1) {
            s++;
        }
    }
    if(s > 2) {
        s = 2;
    }
    cout << 2 - s << "\n2\n1 2\n";
    return 0;
}