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#include <cstdio>
#include <iostream>
#include <vector>
using namespace std;

int main () {
    int n;
    scanf("%d", &n);
    int ile1 = 0;
    for (int i = 0; i < n; i++) {
        int x;
        scanf("%d", &x);
        if (x == 1)
            ile1++;
    }

    if (ile1 >= 2) {
        printf("0\n");
    }
    else if (ile1 == 1) {
        printf("1\n");
    }
    else {
        printf("2\n");
    }
    printf("2\n");
    printf("1 2\n");
    return 0;
}