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#include<cstdio>

int main(){
    int n;
    scanf("%i", &n);

    int x = 0;

    for(int i = 0; i < n; ++i){
        int a;
        scanf("%i", &a);

        if(a == 1){
            ++x;
            if(x >= 2)
                break;
        }
    }

    x = 2 - x;

    printf("%i\n2\n1 2\n", x);
}