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
32
33
#include <bits/stdc++.h>

using namespace std;

int main(int argc, char** argv)
{
	ios::sync_with_stdio( false );

    int n = 0;
    cin >> n;
    
    vector<int> numbers(n);
    for (int& i : numbers)
        cin >> i;
    
    sort(numbers.begin(), numbers.end());
    
    if (numbers[0] == 1 && numbers[1] == 1)
    {
        puts("0");
    }
    else if (numbers[0] == 1 || numbers[1] == 1)
    {
        puts("1");
    }
    else
    {
        puts("2");
    }
    printf("2\n1 2\n");

    return 0;
}