1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
#include<bits/stdc++.h>
#define FOR(i,a,b) for(int i=a;i<b;++i)
#define FOROP(i,a,b,op) for(int i=a;i<b;op)
#define FORD(i,a,b) for(int i=a;i>=b;--i)
#define PB push_back
#define FI first
#define SE second
#define umap unordered_map
#define uset unordered_set
#define vi vector<int>
#define vii vector<vi>
#define pii pair<int, int>
#define ALL(X) (X).begin(),(X).end()
#ifndef DEBUG
#define endl (char)10
#endif
using namespace std;
using ll = long long;

int main () {
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    int n;
    cin >> n;
    int jc = 0, p;
    FOR(i,0,n){
        cin >> p;
        if (p == 1) jc++;
    }
    cout << 2 - min(2, jc) << "\n2\n1 2" << endl;
}