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#include <cstdio>

int main() {
    int number_of_ones = 0;
    int number_of_vert;
    scanf("%d", &number_of_vert);
    while(number_of_vert--) {
        int x;
        scanf("%d", &x);
        if(x == 1) {
            number_of_ones++;
            if(number_of_ones > 1)
                break;
        }
    }
    switch(number_of_ones) {
        case 0: printf("2\n"); break;
        case 1: printf("1\n"); break;
        default: printf("0\n");
    }
    printf("2\n1 2\n");
    return 0;
}