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//Krzysztof Pieprzak
#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef long double ld;
typedef unsigned long long ull;
typedef unsigned int uint;
typedef vector<int> vi;
typedef vector<ll> vll;
typedef pair<int,int> pii;
typedef pair<long long, long long> pll;
typedef vector<pii> vpii;
typedef vector<pll> vpll;

#define Size(x) (int)x.size()
#define VAR(v,n) auto v = (n)
#define FOR(i,a,b) for(VAR(i,a); i < (b); ++i)
#define FORE(i,a,b) for(VAR(i,a); i <= (b); ++i)
#define FORREV(i,a,b) for(VAR(i,b); i >= (a); --i)
#define FORSTEP(i,a,b,step) for(VAR(i,a); i < (b); i += (step))
#define FOREACH(i,c) for(auto i : (c))
#define FOREACHS(i,c,n) for(VAR(i,&(c)[0]); i-(c)<(n); ++i)
#define ALL(x) x.begin(),x.end()
#define CLEAR(t) memset(t, 0, sizeof(t))
#define F first
#define S second
#define MP make_pair
#define PUB push_back
#define POB pop_back
#define pieprzu ios_base::sync_with_stdio(0);

const int    INF = 1000000001;
const double EPS = 10e-9;

void rob(int test) {
    int n;
    scanf("%d", &n);

    int number;
    int onesCnt = 0;
    FOR (i, 0, n) {
        scanf("%d", &number);
        if (number == 1) {
            ++onesCnt;
        }
    }

    printf("%d\n2\n1 2\n", max(0, 2 - onesCnt));
}

int main() {
    int test = 1;
    //scanf("%d", &test);

    FORE (i, 1, test) rob(i);

    return 0;
}