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#include <cstdio>
#include <algorithm>
using namespace std;

int main() {
    int n, a, q = 0;;
    scanf("%d", &n);
    while (n--) {
        scanf("%d", &a);
        if (a == 1) ++q;
    }
    q = min(2, q);
    printf("%d\n2\n1 2\n", 2 - q);
    return 0;
}