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// Karol Kosinski 2018
#include <cstdio>
#define FOR(i,a,b) for(int i=(a);i<(b);++i)
using namespace std;

int main()
{
    int n, ones = 0;
    scanf("%d", &n);
    FOR(i,0,n)
    {
        int a;
        scanf("%d", &a);
        ones += int(a == 1);
        if(ones == 2) break;
    }
    printf("%d\n2\n1 2\n", 2 - ones);
    return 0;
}