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#include<iostream>
#include<list>
#include<stdio.h>
#include<map>
#include<set>
using namespace std;
#define ull unsigned long long int
#define FOR(i,n) for(int i=0;i<n;++i)
#define nil 5000
#define znakow 26
int inline min(int a,int b){return a>b?b:a;}
int inline max(int a,int b){return a<b?b:a;}
int main(){
    ios::sync_with_stdio(false);
    int n;
    cin>>n;
    int ones=0;
    FOR(i,n){
        int k;
        cin>>k;
        if(k==1)++ones;
    }
    if(ones==0)cout<<"2\n";
    if(ones==1)cout<<"1\n";
    if(ones>=2)cout<<"0\n";
    cout<<"2\n";
    cout<<"1 2\n";
    return 0;
}