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#include <cstdio>
using namespace std;

int n, a, count_one = 0;

int main() {
    scanf("%d", &n);
    for (int i=0; i<n; ++i) {
        scanf("%d", &a);
        if (a==1) ++count_one;
    }

    if (count_one == 0) printf("2\n");
    else if (count_one == 1) printf("1\n");
    else printf("0\n");

    printf("2\n");
    printf("1 2\n");
}