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#include <iostream>

int main() {
    size_t n;
    std::cin >> n;

    size_t ones = 0;
    for (size_t i = 0; i < n; ++i) {
        size_t a;
        std::cin >> a;
        ones += a == 1 ? 1 : 0;
    }

    std::cout << 2 - std::min(ones, (size_t)2) << "\n2\n1 2\n";
}