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#include <cstdio>
#include <vector>

int main() {
    int originalSize;
    int counter = 0;
    int numberOfOnes = 0;
    scanf("%d", &originalSize);
    while (counter < originalSize) {
        int currentIndexSize;
        scanf("%d", &currentIndexSize);
        if (currentIndexSize == 1) {
            numberOfOnes++;
        }
        counter++;
    }
    if (numberOfOnes > 1) {
        printf("%d\n", 0);
    } else if (numberOfOnes == 1) {
        printf("%d\n", 1);
    } else {
        printf("%d\n", 2);
    }
    printf("%d\n", 2);
    printf("%d %d\n", 1, 2);
    return 0;
}