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#include <cstdio>

int main(){
    int dupa=0;
    scanf("%d",&dupa);
    
    int onecntr=0;
    
    while(dupa--){
        int tmp;
        scanf("%d",&tmp);
        if(tmp==1){
            onecntr++;
            if(onecntr>=2)
                break;
        }
    }
    
    int modifications;
    
    if(onecntr>=2)
        modifications=0;
    else if(onecntr==1)
        modifications=1;
    else //no ones
        modifications=2;
    
    printf("%d\n2\n1 2\n",modifications);

    return 0;
}