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#include <cstdio>

using namespace std;

void printSol(int count)
{
    printf("%d\n2\n1 2\n", count);
}

int main()
{
    int N = 0;
    int ones = 0;
    scanf("%d", &N);
    for (int i = 0; i < N; ++i)
    {
        int b;
        scanf("%d", &b);
        if (b == 1)
        {
            ++ones;
            if (ones == 2)
            {
                printSol(0);
                return 0;
            }
        }
    }
    if (ones == 0)
    {
        printSol(2);
    }
    else
    {
        printSol(1);
    }
    return 0;
}